Nikon Camera and Lens Information and Repair

Version 1.11 (29-Oct-22)

Copyright © 1994-2022
Samuel M. Goldwasser
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Table of Contents



  • Back to Audio and Misc Repair FAQ Table of Contents.

    Preface

    Author and Copyright

    Author: Samuel M. Goldwasser

    For contact info, please see the Sci.Electronics.Repair FAQ Email Links Page.

    Copyright © 1994-2022
    All Rights Reserved

    Reproduction of this document in whole or in part is permitted if both of the following conditions are satisfied:

    1. This notice is included in its entirety at the beginning.
    2. There is no charge except to cover the costs of copying.

    DISCLAIMER

    Although working on cameras is generally less risky than dealing with microwave ovens, TVs, and computer monitors, there is one component in every camera with an electronic flash - even the least expensive throw-away variety - that is potentially lethal. Specifically, it is the energy storage capacito. And of course even more so for separate electronic flash units or "speed lights" with their higher energy. This may charge up as soon as power is turned regardless of whether flash is called for, and may retain a dangerous charge for hours or days. If working inside a camera or flash unit, on one that has had its case damaged exposing internal parts, it is essential that you read, understand, and follow all safety guidelines contained in this document and in the document: Safety Guidelines for High Voltage and/or Line Powered Equipment.

    If there is no electronic flash, the greatest risk is torn flesh from sharp sheet metal or gear teeth. ;-)

    We will not be responsible for damage to equipment, your ego, county wide power outages, spontaneously generated mini (or larger) black holes, planetary disruptions, or personal injury or worse that may result from the use of this material.



  • Back to Audio and Misc Repair FAQ Table of Contents.

    Introduction

    The is random information and some repair notes on various Nikon cameras and lenses I've worked on. Some of this used to be in the Audio FAQ. Originally it was supposed to be only about Digital SLRs (DSLRs) and their lenses, but it will be morphing into covering some aspects of fully mechanical cameras with at most an exposure meter. The latter are just such beautiful examples of what can be done well without high tech electronics.

    Recommended Tools

    Selecting a Type of Digital Camera

    It's possible to spend as little as $0 for a camera (if it's built into your smart phone) or more than $10,000 for a top-of-the-line DSLR or mirrorless camera with an assortment of lenses. There are many Websites with recommendations. Here my quick take on this topic:

    1. Smart phone cameras: If you don't care and don't want to care about the mechanics of taking pictures, use your phone camera. With each successive generation of smart phones, their built-in cameras improve dramatically and provide remarkably good picture quality and features often not available in expensive gear. Due to the mass appeal of smart phones, a great deal of engineering effort and money is put into their design really pushing the state-of-the-art - which in some cases would appear to violate the laws of physics given the teeny lens and sensor of a phone camera. while there are far fewer options when taking pictures, the default set is often perfectly satisfactory. There may even be some that are not commonly available with stand-alone cameras. And while it is sometimes possible to access features like shutter speed that are normally hidden, that will probably be awkward and revealed with a Web search. But your phone is likely to be with you at all times so there are no issues of lugging around 10 pounds of extra photo gear.

    2. Point-and-shoot cameras: These are the next step up incorporating many features of "real" cameras like the ability to control shutter speed and aperture and other photo-geek parameters. ;-) The reality is that in most cases, they will be used in "automatic" mode. For 99% of your photos, the quality will likely be comparable to those from an expensive DSLR or mirrorless camera. And they fit in a pocket and weigh only a few ounces. The typical point-and-shoot camera will have 6:1 to 10:1 optical zoom which for a DSLR would mean a bulky zoom lens with the rig then weighing in at 2 to 3 pounds or more. They will also have a macro (close up) capaility typically being able to focus within an inch or less of the subject, which would require a separate macro lens or special closeup lenses with a full size camera. And FWIW, a mirrorless camera is similar to a point-and-shoot in technology, but with a larger sensor and a price tag 10x to 100x higher. ;-)

    3. DSLRs or mirrorless cameras: Of course for professional photographers it is essential to have control over EVERYTHING. And while these will have various automatic modes, full control will be possible (if rarely used in practice). The potential picture quality can be better due to the large sensor - that's simply the reality of the laws of physics. In practice it may only matter for super huge blowups. Mirrorless cameras are essentially the fancy and expensive version of point-and-shoots with a high resolution LCD viewfinder instead of an optical viewfinder (in addition to the normal LCD display) both fed from the main sensor. ;-)

      One would think that when shooting with a DSLR in "live view" mode (which uses the sensor with the mirror up) it would behave like a point-and-shoot. But this is usually not the case for technical reasons having to do with the way the sensor works: The mirror flips down and the mechanical shutter closes, then it opens for the exposure and closes after the exposure, and then the mirror flips up, and the shutter opens. That's why the entire sequence of events when pushing the shutter button takes a lot longer and is noisier with live view. Try it! ;-(

    In the end, the quality of your photos will depend more on care in composition, lighting, a steady hand, and other factors not part of the camera itself. Technology can help but it doesn't replace these. No matter the cost of the equipment, if the lighting is not balanced or the depth of field is too shallow, the photos will be poor.

    40+ years ago I owned top-of-the-line Nikon film SLRs including the flagship Nikon Photomic FTN body with several Nikon fixed focal length (non-zoom) lenses. Zoom lenses were a pricey extravagance back then. The FTN body alone was around $350 in 1970s dollars, which would be comparable to roughly $2,000 now accounting for inflation. In those days the only assistance was the built-in exposure meter. Focus and aperture were manual. I did my own darkroom work and ended up with a few good pictures and a lot of mediocre ones. Nowadays I have several low-mid level Nikon DSLRs purchased for either $500 new (D5600) or much much less than that on eBay (D70, D80, D3000, D5200, etc.) and several lenses, but what I had been using most before the development (no pun) of this document was a Canon SX710HS point-and-shoot, primarily for Website photos. It was around $100 on eBay several years ago. A D70 (one of two each for $10 on eBay excluding lens but including shipping) has been used for most of the DSLR and lens dissection photos later in this document but it's not clear if the resulting photos are really any better on average than using the Canon.

    So start out with your phone. If that proves to be too limiting, try an inexpensive point-and-shoot and explore its more advanced capabilities. After that, consider a low-end or older DSLR. One that provides many features of more expensive cameras can be had for $150 or less on eBay with a "standard" or "kit" autofocus zoom lens. See if that provides benefits that are not offset by the hassle of lugging around several pounds of photo gear.

    About the Photos Linked from this Document

    Most of the photos were taken with a Nikon D70 in keeping with the historical value of some of the material here. This is especially fitting for the D70 dissection. ;-) A Nikon AF-S or AF-P DX Nikkor 18-55mm f/3.5-5.6G zoom lens was used for most shots. For the lens dissections, the same model lens was used on the camera in most cases. A Nikon Micro Nikkor AF-S DX 40 mm f/2.8G lens was used for the extreme closeups.

    Specific Nikon DSLR Camera Models

    Nikon D70 DSLR

    Nikon D70 DSLR Dissection

    This is called a "teardown" by iFixit.com but will go considerably deeper with more details. And to avoid any copyright issues, it will be called a "Tearup". :) However, don't worry, nothing (so far) has been torn accidentally. ;-) The D70 was chosen for the dissection because it is recent enough that most of the mechanical parts should be similar to those in more modern Nikon DSLRs but old enough that acquiring a sacrificial camera body was affordable. In fact, I bought 3 D70 bodies as "Parts or Not Working" on eBay for a total of $30 delivered and half of that was shipping. Two of the three appear to be just fine, if a bit icky from congealed finger excrement, similar to what happens with remote controls collecting oily residue over time. They were cleaned with alcohol but a bit of ick may still be evident in some of the photos. The third was unable to access the "Compact Flash" memory card, which turned out to be due to a broken connector pin. In principle that could be repaired, but would hardly be worth it for a $10 camera that has essetially no resale value even if in mint condition. So it is the victim for this project.

    There is a D70 repair manual on-line. Search for "Nikon D70 Repair Manual PDF". It has many detailed photos with step-by-step disassembly and reassembly, some explanations, and parts identification.

    I've actually come to like this camera despite having owned top-of-the-line Nikon F film SLRs many years ago as well as the newer D5600 and other D5xxx DSLRs. While the D70 is heavy and clunky (politely perhaps referred to as more "Solid") compared to newer Nikon DSLRs and has limitations, it is relatively simple to use with no excessive creeping featurism, excellent battery life since nothing is really running until the shutter button is pressed as there is no power hog live view mode, has a fast shutter response, and, uh, also takes decent pictures. ;-) This one has a shutter count of around 12K, so it's really only a teen as these things go. ;-) See my general comments on a "Selecting a Type of Digital Camera". You may be surprised at my conclusions.

    The photos may be viewed at: Nikon D70 DSLR Dissection Web Album. (This opens in a single new tab or window depending on how your Browser is set up.) Some of the photos may be rather gory. So send the kids and pets to another room. ;-) These shots start with an intact camera similar to the one being discombobulated, and then the core, various covers (including the back one with the LCD), the microcontroller PCB - essentially almost everything that can be detached with only the use of a screwdriver and by unplugging cables. Reassembly would be straightforward, at least in principle with adequate notes, closeup photos, and some luck. Beyond this point, except for removing the CCD assembly, wires have to be unsoldered or cut. As can be seen, this has now commenced as the necessary chants and incantations to the gods of dead cameras have been issued and notarized. ;-) And yes, a close examination of the photos will reveal that a pair of buttons did disappear before they should have during the disassembly and I didn't notice. Live with it. ;-)

    And as noted in the introduction, to complete the circle, the photos were taken with another D70. ;-)

    Here are the descriptions:

    Nikon D70 DSLR Brain Transplant

    Of the three D70 DSLRs purchased for the dissection below, two worked but one of those had Firmware V1.00, which I thought was the original. (The third one had a broken CF card socket and became the victim.) What, if any, significant difference there are between V1.00 and V2.00, which is the latest, are not known but bringing it up to date was desirable, for purity if nothing else. ;-) While there are instructions for upgrading firmware on the Nikon Website, apparently V1.00 could not be upgraded by the user as the menu option did not exist even after following the instructions for downloading and copying the files to the Compact Flash (CF) card. The third D70 had a broken pin in the CF card socket so it could not save or display photos but appeared to be otherwise undamaged and was used for the dissection. And it had later version firmware. So guessing that upgrade was possible, a brain transplant was called for. ;-)

    First, the battery was removed since various pins on the connectors will be live even if the camera is OFF. The high voltage on the electronic flash components should not be anywhere near this area of the camera so that should not be a concern. The PCB on the bottom of the D70 has the main microprocessor, non-volatile memory, and RAM. The firmware is probably stored in the 29LV160TE 16M bit flash memory IC next to the chip with the Nikon label. So in principle, it could be swapped, but that's above my pay grade. ;-) Replacing the PCB is only a matter of screws and connectors. And the donor PCB had already been removed from its host during the dissection. Of course, nothing is ever quite so simple as there are at least a half dozen screws of several different lengths and their heads look identical, so either (1) care must be taken to arrange the screws in the correct relative positions after each is removed or (2) they can be compared to the unmodified D70. All the screws around the perimeter of the bottom cover must be removed along with the one on the bottom of the front lens housing, but not the inner ones that secure the metal base/shield inside the cover. Then cover can be angled up and slid off of the USB connector on the PCB.

    There are 5 ribbon cables that need to be unplugged. For all except the large one at the end next to the Nikon chip, the black fasteners flip up; for the remaining one it slides out. If a wrong move is attempted something may break and it may not possible to assure the cables make good contact with the connector pins. Once the fasteners are released, the cables will slide out. The 4 large-head silver screws securing the PCB can be removed and the PCB will unplug from a white connector underneath and slide out of the USB housing.

    Reassemble in reverse order. There are one or two cushy gray conductive pieces that technically should be replaced but they popped out when the PCB was removed and I could not determine where they went. So be it. ;( ;-) Taking the bottom plate off the other working D70 to check is not going to happen.

    After reassembly, it was possible to upgrade the firmware so the 2 working D70 are now similar.

    Then I was looking at the camera and realized that the reason the firmware would not upgrade was probably that it was actually a D70S, NOT a D70, though the V1.00 firmware may still have been out of date. There is no on-line way to upgrade the D70S firmware even though it appears as though the current revision may be something like V1.30. And some further digging revealed that the D70 V2.00 firmware is probably very close to the latest D70S firmware. So if that being totally confusing, it's staying the way it is until a reason appears to justify ripping the camera apart again. ;-) Since all functions I've tested seem to work with the D70 brain board (with V2.0 firmware) in the D70S camera, my conclusion is that there is no difference in the firmware.

    The Franken-camera appears to work correctly and the photos look similar to the those from the other D70. However, what is not known includes whether there are actual physical differences between the D70 and D70s, and if there is a CCD defect map stored in a chip on the mainboard, which case it would not match. Nothing obvious has appeared but who knows? Most of the pics linked from here were taken with this camera so it appears to work well enough. ;-)

    But a while later when attempting to set up a separate LCD monitor for viewing the photos after shooting, this camera does not recognize that a video cable is plugged in while an original D70 worked as described in the manual. It is not known whether this is a preexisting condition, damage caused by the transplant, or something else. Since the video plugs directly into the brain board, which is from a D70, it should behave like a D70. Lack of video is not a great loss though since the output from the camera is low resolution with mediocre quality and would be just barely useful anyhow - perhaps to confirm that the picture is framed correctly but not much else.

    Nikon D70 with Corrupted Memory Data

    This may occur with other models but happened twice with a D70. When the battery charge is marginal, the camera may work erratically. For the D70, the top LCD displayed "CHG" but didn't lock out all functions. For example, AF may beep but the shutter won't trigger. And if it does, data written to the memory card may end up being corrupted. The camera will then display "There is no Data", "Memory Card is not Usable", or some similar error. Previous photos may not be accessible. And, USB transfer to a PC is likely to abort part way through or just hang.

    Don't panic as the previously recorded photos should still be present. But a suitable USB memory card reader may be required to recover them. Multi-format memory card readers are available for a few dollars on eBay and elsewhere if your PC doesn't have the capability built-in. Confirm that the model you select supports the memory card format! Many may not support the old CF format of the D70. Write capability is not necessary as it should be possible to format it in-camera, or in a Canon camera ;-) if that doesn't work. Formatting is recommended after the photos have been recovered to assure the card's file system is not corrupted.

    Nikon D80 DSLR

    Nikon D80 DSLR Dissection

    The Nikon D80 is generally similar to the D70 in appearance but with a 10 MP resolution instead of 6 MP and also has a much larger LCD on the back panel, which is actually useful for reviewing photos (though no "Live-View" mode). It uses an electronically timed focal plane shutter rather than selective readout of the CCD as in the D70. Ironically the mechanical shutter has advantages, particularly with respect to minimizing blooming of highlights.

    There is a D80 repair manual on-line. Search for "Nikon D80 Repair Manual PDF". It has many detailed photos with step-by-step disassembly and reassembly, some explanations, and parts identification.

    The $25 D80 selected for the tearup has problems with the gears driving the mirror and displays "Err" in the top LCD after valiant whirring attempts to reset it. This is repairable based on various Web videos, but requires an almost total teardown ;-) of the camera to be able to replace the motor assembly and/or large white gear. So while the tearup will reach that point, reassembly is probably not going to happen. ;-)

    All photos were taken with the same D70 used for its portraits. ;-) I do have a working D80 but that may eventually be sold. Since its shutter count is over 66K, adding to that was not desirable. The shooting conditions are similar to those for the D70 with the same settings for Web Album Generator.

    The photos so far may be viewed at: Nikon D80 DSLR Dissection Web Album. (This opens in a single new tab or window depending on how your Browser is set up.)

    Here are the descriptions:

    There may be more photos to come.

    If what you want is entertainment with a bit of useful information, check out the YouTube video Prime Studios - Destroying a Nikon Camera or Web page with still shots PetaPixel - Step-by-Step Teardown of the Nikon D80 Shows You What's Inside a DSLR. Thankfully, both of these are the same D80 and it had already been fatally damaged before he got a hold of it, so the gore is tolerable. ;-)

    For the specific problem this D80 has, namely the whirring gear error, there are a pair of more serious YouTube videos at Nikon D80 ERR Split Gear Part 1 which covers the disassembly to access the gear motor and Nikon D80 ERR Split Gear Part 2 which covers the installation of the replacement and then reassembly of the camera. And of course since there are a lot of shots of the camera in various stages of discombobulation nearly to the bare bones, it also serves as a decent dissection, though attempting to keep track of what screws were removed at each step may be rather challenging.

    For this camera, the black gear attached to the motor shaft is indeed fractured so the motor spins with fully doing what it's supposed to do, but whether that happened on its own or was the result of excessive torque driving the mirror / shutter mechanism due to some other issue such as a faulty encoder position sensor is not known and I'm not really inclined to go to all the trouble of replacing the gear and reassembling the camera to find out. Sorry. ;-) Though the expense at least wouldn't be much as the gear in my dissected D70 is the same. Even if I didn't have that, there are over 100 listings on eBay for the gear, some under $3. It must be a common failure. And for someone with an attention to detail in keeping track of everything during disassembly (especially the locations of the solder joints for the dozen or so wires that need to be disconnected), repair should be straightforward if not cost effective. ;-)

    And to top it off, I accidentally removed the motor mount (not just the motor and gearbox itself via the two large-head screws) and lost one of the rollers without even realizing it until the mirror would not come all the way down. Miraculously, I did find the roller later on the workbench and reinstalled it, but that's the reason why the mirror is in the fully up position in the Mirror Box photos rather than down as would have been preferred. ;( :-)

    Nikon D3000 DSLR

    The D3000 is the first of the D3xxx series of entry level DSLRs. But it still has enough features to make it a worthwhile camera. And it's a bit smaller and lighter than many or most of those before it like the D70 or D80 and the slightly fancier 5xxx series.

    Nikon D3000 DSLR Dissection

    This will be coming once I acquire a suitable sacrificial D3000 body. So far, both of those I've gotten don't qualify. One worked fine and the other was easily repaired. ;( ;-)

    Coming soon. Photos of an intact D3000 may be viewed at: Nikon D3000 DSLR Dissection Web Album. (This opens in a single new tab or window depending on how your Browser is set up.) But that's so boring.

    Nikon D3000 with Dead LCD

    This may apply to other models but was seen on a D3000 sold for next to nothing because the LCD did not display any text or graphics, though the back-light was working.

    There is an internal flex cable running from near the center of the back panel assembly inside the rear cover of the camera to the LCD itself. It attaches to a "zero insertion force connector" - the ones with the thin lid that has to be flipped up to insert or remove the cable. In this case the cable is short and just barely reaches the connector. So even though additionally secured with a piece of tape, it apparently pulled out over time or more likely was never inserted quite correctly in the first place as that is a bit challenging. Voila, nothing on the LCD, only the back-light.

    The rear cover of the camera is secured by 2 screws on either side, 2 screws near the viewfinder (partially hidden by the rubber eyepiece cup if present), 4 screws along the back edge of the bottom, 1 screw further in, and 1 screw under the rubber cover next to the battery compartment latch. There are several different size screws so make sure to set them aside labeled as to their origin. Once the screws have been removed, the rear cover can be popped off, perhaps with the aid of a thin blade. CAUTION: It is connected to the main board via another zero insertion force connector near the bottom so take care not to rip it.

    With the rear cover separated from the body, the problem will be obvious. Remove what's left of the small piece of tape, flip up the latch, and carefully insert the cable so that it extends underneath the edge of the connector as far as it will go, and then flip the latch down. Then add a larger piece of Kapton or similar tape to help secure it. Or a bit of 5-Minute Epoxy. Camera operation can be carefully confirmed with the back in place but before installing the screws.

    Nikon D5300 DSLR

    The D5300 is mid-way through the "entry-level" or "upper entry-level" class of Nikon DSLRs depending on who is doing the classifying. The D5600 is believed to be the current version (as of 2022) but the D5300 is fairly close with the same resolution and most of the same capabilities. Among the differences are that the D5600 has a touch screen (which IMO responds when not expected more than often than not), lacks GPS, and has a normal Micro USB instead of the Nikon UC-E6 connector. ;-)

    Nikon D5300 DSLR Dissection

    The following uses photos of 2 different D5300s: One was purchased as "Parts" - literally - as it had already been partially disassembled, apparently in a serious effort to repair it that went wrong. The sets of screws were separated into individual baggies and whoever was doing this did try to avoid damage. Some parts were not included though like the SD cover and front-right hand-grip. The other one was purchased as "Dead", which indeed is an accurate description. It does absolutely nothing but looks nice. ;-) My fantasy is to take the parts camera mainboard and swap it into the dead one and have it come back to life. But there's no way so far to know if mainboard is the problem, the "parts" mainboard is any good, or even went with the other parts.

    The photos were taken with the second working D70 / D70s following its brain transplant. ;-)

    The photos so far may be viewed at: Nikon D5300 DSLR Dissection Web Album. (This opens in a single new tab or window depending on how your Browser is set up.)

    Here are the descriptions:

    More to come, perhaps.

    Specific Nikon DSLR Lenses

    The following are more descriptive with only a few fairly simple repairs. On a scale of 0 to 10 modern lenses like this rank around -10 in ease of repair, at least for someone who hasn't dealt with them before. ;( Anything requiring more than the simplest disassembly is almost certain to make things worse and likely result in the thing turning into a high-tech paperweight - at least the first few times it's attempted. Where manual focus doesn't work on an autofocus lens, live with it. ;-) Even being able to lubricate the proper surfaces is likely to require extensive disassembly and the opportunity to tear a ribbon cable, break a connector, or lose itty-bitty screws or other almost invisible parts. For many Nikon lenses like this, there are (supposedly) original Nikon repair manuals on-line but don't expect there to be much in the way of real help. They make many assumptions, don't even go deep into some major assemblies, and suffer from poor English translation. In addition, depending on what was disturbed, some specialized test equipment and software may be required to tweak alignment. In fact it is hard to imagine that repair of a relatively low-end lens like these is ever really done by Nikon or an affiliate! And now with eBay, fully functional used specimens can be had for a fraction of the cost of the simplest professional repair.

    Having said that, there are a few repairs that can be tackled without a great deal of experience with a reasonble chance of success. These include replacement of the plastic Nikon F Bayonet Mount on smaller lenses that can get damaged easily, to replace a bashed front lens group, or to replace broken focus/zoom roller/guides in some specific models. Replacing a bashed back lens group on many lenses in theory requires doing optical alignment, which is not possible without the proper high tech equipment and training). How well the lens would work without this is not known. The Bayonet Mount may be available at reasonable cost but anything else is likely to have to be cannibalized from a similar lens. So what's the point other than for the challenge or excitement value. ;-) If you do decide to take the plunge on a more involved repair, take photos at every step even if there is a repair manual available evem of how it goes back together seems obvious when taken apart. It may not be obvious an hour or day later - or even a minute later. Label parts that fit together with "match marks" of some sort like coded scratches or white paint. Many assemblies may appear to have 3-fold symmetry, but that doesn't mean they will work correctly if the wrong choice made. In some cases it isn't quite 120 degrees; in others there are subtle differences preventing engagement of various parts. In short, adding match marks during disassembly is essential to retaining sanity when putting it all back together. Where a repair manual exists, it may references specific features but this is hit or miss. Segregate screws as well since not all the teeny-tiny screws are identical. Work on a surface where tiny parts won't go bouncing off to oblivion. There are unique screws for plastic and metal, and of different diameters and lengths. A padded surface may be useful as well as a magnetic pad to "store" screws and such. Many of the threaded holes are into soft plastic so stripping them is always a risk. If a screw seems tight, it's probably the wrong size. A set of quality Jeweler's or miniature precision Philips screw drivers with magnetic or magnetizable tips is a must.

    If a dozen of the identical model lenses need repair, then after the first 8 or so, this will become straightforward. ;-) But "identical" really means exactly the same model - the design of most of the half dozen 18-55mm lenses differs enough that becoming familiar with one doesn't help much much with any other. For example, even the AF-S 18-55mm VR and VR II lenses are totally different beasts with respect to disassembly and parts replacement since they are different design generations. Only the VR and non-VR versions of the AF-P 18-55mm may be close enough for government work but is not yet known for sure. This most likely applies to other lenses as well.

    These aren't like your great uncle's SLR lenses - and even those were basically impossible to repair without proper precision tools, most excellent eyesight and/or a microscope, and a steady hand. There are serious high tech parts in Auto Focus (autofocus or AF) Vibration Reduction (VR) zoom lenses including a miniature motor and possibly a gear train, angle encoders and other sensors for zoom and focus, MEMS gyros and voice coil actuators, PCBs with highly integrated ICs including a microcomputer, and many fragile flex-cables and connectors. In short these are complex intricate electro-mechanical systems, not just a bunch of optics! Though even the basic "kit" AF-S DX Nikkor 18-55mm f/3.5-5.6G VR zoom lens has 11 individual optical elements including one that is aspherical, and others like the Nikon AF-S DX 18-200mm f/3.5-5.6G ED VR II may have 16 or more.

    And while modern lenses in this class are amazing feats of mechanical design with sophisticated electronics, they do NOT have the look and feel of older "dumb" lenses with milled aluminum focus and aperture rings on well lubricated tracks. ;-) Rotating parts in these lenses are nearly all molded/formed plastic constructed with mostly sliding parts with minimal lubrication and a few rollers (but without frictionless bearings) in a few key places. There is no precision machine work to admire and forget silky smooth operation. Even on a brand new lens, this is obvious when rotating the Zoom Barrel. Having said that, they work remarkably well and provide features like autofocus and vibration reduction that one could only have dreamt about with older gear. I do not know whether high-end modern lenses are constructed any differently, but these are what most of us can afford. ;-) And even they typically have a cost if purchased new of several hundred to over a thousand dollars.

    Where there is a Nikon repair and/or parts manual available on-line for the specific model lens, a set of search terms is provided to find it. Should they fail to return anything useful because of decayed links (which is unlikely), I have copies available for the asking. If there is no exact match, a repair manual for a slightly different model lens could prove useful even if the details are not same. But the "repair" manuals are really just disassembly and reassembly manuals with little to no diagnostic information, no explanations of principles of operation, and generally don't go down into the nitty-gritty where the real challenges are in putting things back together. Even the "parts" manuals do not break the lens down below the level of the core (where much of the optics and VR assembly is). They are partially in Japanese and make many assumptions about the user's level of expertise. And while theinfo on alignment - often required after replacing some parts or even just reinstalling them - is quite detailed, it assumes the use of Nikon proprietary jigs and software. But there are numerous diagrams and photos, though none provide the level of detail below with respect to AutoFocus (AF) and Vibration Reduction (VR) implementation. In fact, over half of the typical manual is devoted to the post-repair calibration.

    The largest collection of on-line repair and parts manuals for Nikon equipment appears to be at Learn Camera Repair. That Web site can be searched which will probably be quickest and the manual downloads are all free. However, some others may have manuals not there. They may not be free so make sure that a free download site hasn't been overlooked. Even so, sometimes there are enough free "Preview" pages to be useful. Or the typical cost of under $10 may be worth it if you are really serious about tackling a dicey repair.

    Note 1: Most of the lenses discussed here have "Vibration Reduction" (VR) - a "Steadicam" of sorts inside the lens - which reduces the effects of camera shake especially for telephoto shots. Most popular lenses today have this feature. One would think that the non-VR lenses with the same name will be mechanically similar and thus the descriptions, etc. will also be similar sans references to the VR components. Apparently, this is not so. For example, comparing the repair manuals for the AF-S DX Nikkor 18-55mm/F3.5-5.6G VR and AF-S DX Nikkor ED 18-55/3.5-5.6G show them to differ significantly, possibly because the non-VR version is an older design. (The ED II version may be somewhat similar though.) Perhaps for lenses sold today, they would be similar. But manuals for those are not available on-line yet.

    Note 2: The names for the same lens may differ subtly in various locations in this document, and in the photos and Web Albums. In some instances this is because characters like "/" cannot be used in a filename. But most often it's that I was not consistent when originally assigning names and am too lazy to go back and correct the 75 places where they are screwed up. The differences are irrelevant and anyone with at least the intelligence of a carrot should be able to figure out to which lens they apply. Live with it. ;-)

    Comparison of Nikon DX 18-55mm "Kit" Lenses

    No, these aren't assembled using step-by-step instructions like Heathkits™. ;-) That would be quite a challenge. The term "Kit" applies to lenses bundled with entry to mid-level DSLRs (though also sold separately), specifically AF-S or AF-P DX 18-55 mm zoom lenses. DX refers to the sensor size of ~0.6x1.0 inches, around 2/3rds of the dimensions of the full frame (FX) format of more expensive DSLRs and antique 35 mm film cameras. The zoom range of DX 18-55 mm goes from modest wide angle to modest telephoto - equivalent to approximately 24-83 mm for the FX format. If you're old enough to recall the days when zoom lenses were a high priced luxury, a fixed 50 mm was the "Standard" lens, in the middle of the effective range of the 18-55 mm zoom lenses. For the casual photographer (who still wants to deal with a DSLR at all!), one of these lenses is probably all that is needed. (Or two, one as a backup if one is dropped!) They are relatively compact, light weight, have similar and very acceptable optical performance, and cover most shooting situations without fuss. They all autofocus quickly, quietly, and reliably. Most have "Vibration Reduction" (VR), essentially a "Steadicam" of sorts built into the lens, which is definitely worthwhile, especially at the telephoto end of the zoom range. Although list prices may be in the $300 range, in 2022, any of the lenses covered in the sections below can be purchased used on eBay guaranteed working and in decent cosmetic condition for under $60 delivered, and with luck and patience for under $35. Although versions may be available without VR, it makes little sense to bother with them as the cost won't be much lower, if at all - and due to the whims of sellers or of auction fever, could be higher. Of the three with VR, the AF-P VR lens is probably the most reliable and easiest to repair (or at least easiest to reassemble - pending me being successful, which should be coming soon). However, it will not work with older DSLRs. The runner-up would be the AF-S VR II (which I like based on its look and feel). The reliability of the AF-S VR and VR II is probably similar, but the not-II VR version may be the most finicky to repair despite there being an on-line "repair manual" for it. They all take good pictures, though the AF-S ED may be a bit lower in this respect due to its simpler optical architecture (fewer lens elements) but that isn't really known. It may be that the lack of VR allows it to be simpler without sacrificing optical performance. The Web is dripping with reviews comparisons of all these and what's here is not inteded to compete with them. ;-)

    Here is an implementation summary of known DX 18-55mm f/3.5-5.6G zoom lenses. There may be others:

                Gener-   (1)     Auto-   Focus     Focus       Manual       Year
       Model    ation   Optics   Focus  Encoder  Tachometer    Focus     Introduced
    --------------------------------------------------------------------------------
     AF-S ED      1   2C/5G/7E    SWM     Yes     Magnetic   Mechanical   2005
     AF-S ED II  1.5  2C/5G/7E    SWM     Yes     Optical    Mechanical   2007? (2)
     AF-S VR      2   3C/8G/11E   SWM     Yes     Optical    Mechanical   2007
     AF-S VR II   3   3C/8G/11E   SwM     Yes     Magnetic   Mechanical   2014
     AF-P         4   3C/9G/12E  Pulse    No        None     Electronic   2016? (3)
     AF-P VR      4   3C/9G/12E  Pulse    No        None     Electronic   2016? (3)
    

    Notes:

    1. C: Lens Clusters, G: Lens Groups, E: Lens Elements. "Clusters" are my terminalogy for the Lens Groups that move independently when changing the zoom setting. Lens Groups may be a single Lens Element or a glued combination like an achromat. Lens Elements are individual optics which may be glass or plastic, Extremely low Dispersion glass (ED), and may be normal (spherical) or aspheric. See the specific lens architecture diagrams in the lens dissection Web Albums for details. A Web search for the specific model lens should also turn up more details on the the optics.

    2. Based on appearance, the AF-S ED II lens is believed to be most similar to the AF-S VR physically, but uses the ED optical design.

    3. Since the pulse / stepper motor for autofocus is inherently digitally precise, no encoder or tachometer is needed. It's not primarily to reduce cost. ;-)

    4. If considering buying one of these on eBay or elsewhere, carefully compare the title/description to the actual photos. With 6 models to choose from, the sellers often get it wrong. The simplest place on the lens to check is the label on the front.

    The AF-S ED is probably the original AF-S 18-55mm zoom lens. The ED II may be more similar to the AF-S VR without VR than the ED. The non-VR version of the AF-P 18-55mm lens is identical in appearance to the VR version except for the labels and based on a Nikon brochure appears to have the same optics as the VR version.

    A montage showing stock photos of all known versions of the 18-55mm kit lenses as of 2022 may be seen at: Nikon AF DX 18-55mm f/3.5-5.6 "Kit" Zoom Lenses. These are from Nikon lens product or review pages (copyright © Nikon Corporation) scaled so the relative sizes are close to correct. Photos of actual specimens coming soon.

    Note that the AF-S ED, ED II, and VR lenses have a filter mount that rotates with focus. This can be a pain if desiring to use a linear polarizer to enhance contrast or even an asymmetric lens hood since its orientation should remain fixed. What were they thinking? ;( It is fixed on the AF-S VR II and AF-P lenses.

    Diagrams showing the physical appearance and optical architecture of the 3 VR lenses may be found at: Comparison of Nikon DX 18-55mm 1:3.5-5.6G VR "Kit" Zoom Lenses.

    AF-S DX 18-55mm VR Zoom Lens Zoom Control:

    The following applies specifically to the AF-S DX 18 55mm VR Zoom Lens but others are generally similar. Although the design of the mechanism that moves the internal parts of the lens when zoom is changed may seem daunting, it is really quite straightforward. But putting the pieces back together can be a challenge.

    Another challenge has been locating truly broken specimens of these lenses that I'm willing to use for dissection. Lenses listed on eBay as "For Parts or Not Working", "Untested", or even "Manual Focus Only" have turned out to be fully functional or easily repaired without going deep inside. In some cases it's because the lenses are not compatible an older camera the seller used for testing and so appear not to work. For others it's simply because the seller had no camera body to use for testing and they didn't want to risk a return. But overall, the reputation for poor reliability of AF-S lenses appears to be exaggerated. In fact I've yet to acquire an intact sample of a "Parts" AF-S where the SWM (Silent Wave Motor) or driver electroncs were faulty.

    More to come.

    Nikon Lens Replacement Parts

    Should it be determined that a specific part is defective and that it is likely to be within your experience/skill level to replace it, where to find a replacement? With a very few exceptions, Nikon will not be useful except for "peripherals" like caps and hoods. (And perfectly satisfactory non-Nikon versions are for these are available at a fraction of the genuine ones.) eBay and Amazon have numerous listings for lens parts, but these must be taken with a grain of optical sand ;-) as the sellers often have no clue about the differences among lenses. (This also applies to sellers of the lenses themselves!) So the listing photos must be carefully examined to determine if they even apply. A large percentage will be for a totally different lens and will not be compatible. And forget about the main PCB with the CPU and memory if your lens isn't recognized by any camera. They may have parameters in NVRAM optimized for the specific lens. Searching on eBay for "nikon 18-55mm vr ii lens (motor,parts,pcb)" (or whatever the specific lens is) should turn up sample listings. Amazon searches may need to be more specific as their search engine is brain-dead from a practical point of view (though perhaps not for maximizing their profits). The ridiculous prices the sellers are charging for most replacement parts can be quite amazing (and amusing). ;-) In fact, given the relatively low cost of used or "parts" lenses, it almost never makes sense to buy individual parts.Two exceptions may include the cheesy plastic bayonet mount plate and possibly the front lens group (cluster), which may be reasonably priced and easy to replace. The cost of other parts may exceed that of an entire working replacement lens. But if VR isn't working in a VR lens, it is unlikely the VR Assembly can be installed by mere mortals even if it is the correct type. That requires nearly total disassembling the lens. (The on-line repair manuals don't even go that deep.) And the problem may not even be in the VR Assembly. Furthermore, specialized Nikon test equipment and proprietary software are required to calibrate the lens after repair with parameters stored in NVRAM. And if VR isn't working, perhaps it's because the lens you bought is not actually a VR lens and the seller had no clue. ;( ;-) That is very common.

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G ED Zoom Lens

    There is a repair manual on-line for this lens. Search for "Nikon AF-S DX Nikkor 18-55mm f3.5-5.6 ED Lens Service Manual" (without the quotes). It's the second hit using Google. This manual may be slightly more detailed than the later ones, though some of the steps need more context to make sense. ;(

    The ED may be the first of the AF-S DX 18-55mm zoom lenses and not much is known about it other than what is in the repair manual showing significant differences compared to even the ED II version. That version appears to be closer to the AF-S VR lens, below.

    The AF-S DX ED has fewer lens elements, uses a magnetic instead of an optical tachometer for autofocus, and the construction is more complex and somewhat clunkier.

    I acquired one but since it is in good condition post cosmetically and functionally, it will be for external inspection only, not for dissection. There are no current plans to investigate this lens in greater detail unless someone would like to donate a sacrificial specimen for analysis. The asking prices on eBay are above may curiosity quotient for a lens to take apart and likely never put back together so it functions. ;-) Appropriate chants and incantations will be issued to the gods of dead camera lenses upon request but it will not likely survive the experience. :( ;-)

    See the Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G ED Zoom Lens Dissection Web Album. There is no dissection yet but it shows some stock photos, the optical architecture, how the lens groups move with zoom, an engineering diagram of the lens derived from one in the repair manual, and photos of the exterior in various poses. Most of these photos were taken with either a Nikkor 18-55mm ED II lens or the repaired 18-55mm ED lens - ID# 2.

    Here is a summary of the Nikkor 18-55mm AF-S DX f/3.5-5.6G ED lenses I've acquired so far:

    1. ID #1 (SN: US2834999): Fully functional.

    2. ID #2 (SN: US2053837): Loose wobbly noisy Filter Ring resulting in erratic zoom and inability to focus. The cause was broken tabs causing the Focus Fork to not lock in place. Filter Ring only held in place by Trim Ring. Repair below.

    3. ID #3 (SN: US2424548): Rear guide tube shroud / light shield loose inside lens visible in eBay listing photo. This lens is in absolutely mint external physical condition - perfect like new. But the innards are all twisted. ;( After removing the back parts (Inner Ring, Bayonet Mount, Camera Contact Strip), it was obvious this lens had been subject to extreme trauma. That loose part is a flare shield that moves up and back independent of the lens groups. But it has no optics, just a big hole. There was major obvious damage to the straight metal tangs that operate the zoom and aperture. All were bent and had even popped out of the slots they are supposedd to engage, almost certainly from excessive torque being used to attempt to change the zoom setting. Once these were straightened and reinstalled, it became obvious that this wasn't the tangs' fault. There is something seriously wrong with the spiral tracks on which the front and back lens clusters move. But exactly what it is is not at all clear. They look perfect. While they move freely by hand, they are almost impossible to move via the tangs when rotating the Zoom Barrel and would definitely become twisted again even. though they are quite beefy. In addition, the lever on the aperture assembly that operates the iris diaphragm itself got scrunched (technical term!) and in straightening it, a piece broke off. But that doesn't appear to be essential but may be there just to prevent the aperture tang from going in the wrong slot so no effort will be made to reconstruct it. With everything straightened, when installed in the only orientation that makes sense, the lens group/aperture assembly would fall out into the space between the Filter Ring and the front of the zoom spiral tracks. Which makes no sense at all. There is no other obvious damage that would appear to be problematic - the thing just won't zoom. Since this is a balancing act between the torque applied by the Zoom Barrel parts and the friction of the spiral grooves, I am wondering it some lubrication was never applied properly and the lens somehow passed final test. That is a stretch though. With the back lens group / aperture assembly removed it operates smooth as silk.

      With all the parts installed but still in the unzoomable state, it was reassembled to see what it would do. The results of that test were mixed. It did attempt to focus and would take pictures of sorts, but they were out of focus and strangely colored. At that point the aperture was not operating and the back lens cluster may have falled out the bottom again. But it's likely that the electronics are fine. For all the good that does.

      So there are two mysteries here:

      1. Why is it virtually or totally impossible to rotate the zoom ring and have the back lens cluster move smoothly or at all without twisting the zoom and aperture tangs out of shape again even though everything appears to be perfectly aligned and undamaged (after untwisting)? In fact, lens ID #2 requires about the same torque to move zoom through its entire range as this lens does with the back lens cluster totally removed. "It still looks like a lens.". ;-)

      2. Why does the back lens cluster fall out of the guide at the front if zoom is set near 55mm even though it appears to be installed with the correct orientation?

      If it weren't for (2), perhaps the lack of lubrication would make sense. There must be an obvious cause common to both of these but so far identifying it has proven elusive. This may call for another acrificial lens to compare! ;-)

      Additional photos have been added to the dissection Web Album reflecting the extent to which it has been disassembled, and more info should be forthcoming. Stay tuned.

      The Filter Ring is in mint condition, so it could be swapped into ID #2. But since that would also swap the front lens groups, it is not known whether there might be collateral image quality issues without the Nikon-certified alignment. And since ID #2 is no longer broken, why fix it? ;-)

    Repairing Broken Focus Tabs on Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G ED Zoom Lens

    Neither focus mode worked on this lens (ID #2), zoom was erratic, and if zoomed out with focus at the closeup-end (also extended), the Filter Ring was very loose and would have fallen off if the Trim Ring wasn't preventing that. At first I thought the problem might be similar to the one described in the section: Repairing Loose Front on Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens.

    Autofocus on this lens as well as the AF-S VR (and probably the AF-S ED II), and other lenses use the SWM to rotate a plastic ring with two prongs (tips of a fork) that slip into slots in the Filter Ring, which serves to adjust focus by moving in and out via internal helical grooves. On this sample of the AF-S ED lens, two of the raised bits of plastic that are the stops on one side of the slots were sheared off. While they aren't that large, it still isn't clear how this could happen. Possibly a gorilla attempted to change focus using the Filter Ring while in autofocus mode. Or perhaps there was a control problem resulting in the fork bashing against one end repeatedly. However, testing after the repair (below) did not indicate any such issue.

    The broken protrusions are only about 1/16" on a side. But a replacement can be long since there is nothing in the way around the periphery of the Filter Ring. However, gluing plastic is always dicey so I opted to install a pair of 0-80 x 1/16" cap head screws in place of the broken-off plastic bits.

    Since the repair manual is fairly detailed for this lens, it may come in handy here to clarify the disassembly/reassembly process.

    1. Remove the Rubber Grip by carefully lifting one edge and then pulling it off incrementally around its periphery.

    2. Peel off the strip of polyester tape securing the Trim Ring to the Zoom Barrel. It may be possible to re-use this but don't count on it.

    3. Set the AF A/M switch to "M" and rotate the Focus Ring clockwise to the fully extended position. Set the AF A/M switch to "A" so it stays there.

    4. Set zoom to the 55mm position.

    5. Slide the Trim Ring away from the body of the lens so it rests against the Filter Mount at the front.

    6. Check the position of the two tips of the plastic "fork" that engage the outside of the Filter Ring. With these zoom and focus settings, they should be barely on the Filter Ring (<1/8th inch). In the case of this failure, they may be at almost any location and the Filter Ring can be removed now if it doesn't just fall out on its own.

      Nikon AF-S DX Nikkor 18-55mm 1:3.5-5.6G ED Zoom Lens Filter Ring Focus Repair shows the normal appearance and after the repair. Sorry, I forgot to take a pic of the original condition. :( ;-)

      If they are correctly engaged, the problem is elsewhere.

    7. The Trim Ring can be removed from the Filter Ring by carefully squeezing the Filter Ring at the slot positions so they clear the inside of the Trim Ring. But again, this is not necessary.

    8. Inspect the slots in the Filter Ring for the missing protrusions. Two or more of them will likely be sheared off. If only one was broken, the lens would probably still work.

    9. (Optional) Before doing the repair itself, it is possible to somewhat check the autofocus electronics are functional even without the Filter Ring (with the front lens groups) installed. Depending on zoom position, the lens will create a fairly sharp image at extreme closeup - an inch or two from the front of the Zoom Barrel - what's left of the lens. So with the lens mounted on a camera and the Focus Switch set to A, determine the approximate distance where the image appears sharp in the viewfinder and position the camera there. While pressing the shutter button half-way to enable autofocus, move the camera back and forth around that position and observe the operation of the Focus Fork: It should rotate back and forth as well. If it does nothing or consistently slams to one end, then there is something else wrong and that may have been what caused the physical failure in the first place.

    10. Drill a 3/64" hole (which is the correct size for an 0-80 machine screw) in the area where the missing bit would be so that the edge of the screw head will be positioned where the edge of the plastic protrusion was.

    11. Since the plastic is soft, tapping the 0-80 holes may not be needed and in fact using the screws to make tap their own threads may be more secure. In leu of an 0-80 screw, an extra camera or lens screw of appropriate size may be used.

    12. Install the 0-80 x 1/16" screws just snug. Don't over-tighten or there is a risk of stripping the threads.

    13. This step is only necessary if the Trim Ring was removed entirely from the Filter ring: Slip the Trim Ring onto the Filter ring by squeezing it slightly at the area of the slots. Do not secure it. Take care not to dislodge the padded strip on the inner surface of the Trim Ring. If a portion needs to be reattached, it and the surface of the ring should be cleaned with degreaser to remove residual oil and/or grease. If the dangling piece is short, just cutting it off will suffice.

    14. With the zoom and focus still in the extended position, install the Filter Ring so the fork engages the repaired slots. The tips of the fork should just engage them. On the AF-S ED lens (unlike the AF-S VR lens), the Filter Ring can go in at many orientations; only one is correct and the Filter Ring should slip in with no resistance at all. The repair manual shows a reference line on the Filter Ring that should be near a triangular mark on the Helicoid (inner) Ring when they engage correctly. The triangle is easy to spot but the line is just barely visible at the edge of the Filter Ring. And even when found, it is still a bit of hit-or-miss to get the engagement correct. Once engaged, it may make snapping into position easier if focus is set to M and the Focus Fork is rotated slightly counterclockwise so the Filter Ring is recessed a bit when they engage. Depending on which bits of plastic were broken and thus where the screws are located, it may be necessary carefully spread the fork apart to do this. Focus will only work from end-to-end with the correct alignment. It may be worth adding your own reference marks if future repairs are required.

    15. Testing can now be performed both off and on camera.

      CAUTION: Do the testing over a padded surface in case the orientation of the Filter ring is not correct as it may pop off during auto or manual focusing and fall out. That has happened to me a couple of times fortunately resulting in only minor cosmetic damage but it could have been much worse. ;-(

    16. First check that the Filter Ring does not fall off even at the extremes of zoom with focus set to M.

    17. Install the lens on a compatible camera. All functions should work so exercise zoom with auto and manual focus and take some photos and inspect them carefully for sharpness. If focus lock cannot be achieved over the full range of zoom and distance or anywhere, the orientation is incorrect. Recheck it!

    18. Once this test had been confirmed, add a dab of Epoxy to secure each screw. This is best done with the Filter Ring again removed from the lens (Uh!) so as not to get adhesive on the Focus Fork tines or elsewhere. To add some strength, the Epoxy can be extended around the periphery of the ring away from the slots, but not much toward the front. And take care it doesn't dribble where it shouldn't. :( ;-) Confirm that the tines of the Focus Fork will fit in the slots and trim any excess adhesive as required. For reference, the slots are around 9 mm across.

    19. Once the adhesive has set, use an air bulb and/or camel's hair brush to dust out the inside of the lens and Filter Ring, and particularly the exposed lens elements. Then reinstall the Filter Ring as before and reconfirm it is oriented correctly as before!

    20. The remaining steps are the reverse of the disassembly. If the polyester tape cannot be reused, Kapton electrical insulating tape or even thin plastic packing tape should be satisfactory since the Trim Ring is mostly cosmetic, doesn't serve any critical function, and is under minimal stress. Clean the area where the tape goes both on the Zoom Barrel and Trim Ring before replacing it.

    There was some free play when this lens was reassembled because the 0-80 screws weren't quite positioned perfectly. Can you believe that? Geez, they are at least as large a grain of rice. ;-) Also, the heads of the only suitable screws available were ridged, not smooth and after 10,000 years of continuous shooting that could conceivably result in excessive wear of the Focus Fork tines. Of course as a practical matter, neither would likely make the slightest difference in anything including the longevity of the Universe, but being somewhat OCD about such things, a layer of Epoxy was added around the screw heads to to smooth and fatten them up a bit. ;-)

    After around the fiftieth time removing and replacing the Filter Ring, it becomes almost trivial. ;-)

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G ED II Zoom Lens

    I have not found a repair manual or even an exploded parts diagram for this lens, only the boring user manual. If anyone has one, please contact me via the Sci.Electronics.Repair FAQ Email Links Page. The differences between the ED and ED II lenses are fairly significant so the repair manual for the ED version may not even be useful for the gross anatomy. ;-)

    The ED II is the successor to the ED but may be closer in mechanical design to the AF-S DX 18-55G VR that followed. However, it appears to have the same fewer number of lens elements as the ED version also with only 2 lens groups instead of 3. And for that reason, changing zoom requires noticeably less effort. At least for the sample I have. In fact, it may not hold zoom if oriented vertically. Whether this is normal due to excessive wear is not known.

    Investigation of this lens in greater detail is awaiting a suitable sacrificial specimen. And if that turns out to work perfectly, the search will continue. But if someone would like to donate a sacrificial specimen for analysis, appropriate chants and incantations will be issued to the gods of dead camera lenses upon request but it will not likely survive the experience. :( ;-)

    But see the Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G ED II Zoom Lens Dissection Web Album. There is no dissection yet but it shows some stock photos, the optical architecture, how the lens groups move with zoom, and photos of the exterior in various poses.

    1. ID #1 (SN: US5713943): Fully functional.

    2. ID #2 (SN: US6598975): Fully functional.

    3. ID #3 (SN: US6082727): Fully functional.

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens

    This may have been the most popular of the kit lenses, at least based on which model show up on eBay most often. ;-)

    There is a repair manual on-line for this lens. Search for "Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6 VR Zoom Lens Repair Manual" (without the quotes). It's the first hit using Google.

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Description

    The following applies directly to the Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens and probably somewhat to the non-VR AF-S DX Nikkor 18-55mm f/3.5-5.6G ED II. But NOT to the original AF-S ED version, which differs substantially.

    This was the "standard" lens on older D3xxx, D5xxx, and other low to mid range Nikon DSLRs using the DX format (~1x0.6 inch) sensor But there seems to be little standardization among lenses that may appear to be very similar like the AF-S 18-55mm and 18-70mm, which have very little in common in terms of construction. The AF-S 18-55mm has now been replaced with the AF-P version which uses a different type of autofocus motor which simplifies the construction, and is slightly more compact. A description and dissection of that lens is later in this document. But while larger lenses like the 18-200mm are generally similar in construction, the details will differ substantially. A section on those may be forthcoming but even totally broken ones tend to have a cost on eBay above my curiosity quotient. ;-) And there is a Nikon repair manual on-line for the older version of that lens (non-VR-II).

    Further, many lenses like the one in this section are made largely of plastic. The only major structural part made of metal is the cylinder with tracks to guide the extension of the focus and zoom lens groups. (Right of center in the photo above.) And the more recent lenses (AF-S VR II and AF-P VR) have even replaced that with plastic. So it's easy to break parts or strip threads for tiny screws. In fact, the guide rollers which control the extension of the focus and zoom lens groups are plastic, and at least one was found to be fractured in the discombobulated lens used for the photos. It can be seen among the pile of teeny hardware bits.

    But these are very high tech devices.

    Most of the photos referenced below are also available as a Web Album (though possibly at slightly lower resolution) at Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Parts Web Album.

    As if that wasn't exciting enough, here is the good (VR) stuff. ;-)

    There must be some pretty fancy footwork going on in the algorithms on that CPU board to actually implement the VR. And the lens element must be maintained centered electronically when VR is on using the Hall-effect sensors for feedback. There is no restoring force so it will tend to sit at the lowest point. When VR is off, it will be more or less centered using the locking collar. The springs only keep it against the surface of the front cover.

    And you thought camera lenses were boring. ;-)

    Here is a summary of the Nikkor 18-55mm AF-S DX f/3.5-5.6G VR lenses I've acquired so far:

    1. ID #1 (SN: Unknown): Parts lens, no back shell (so no SN), torn camera contacts and other cables. Used for most of the descriptions and photos, above.

    2. ID #2 (SN: Unknown): Parts lens, no back shell (so no SN) and associated parts, no CPU PCB or cable.

    3. ID #3 (SN: US20682964): Front impact damage, broken focus ring rollers. Repaired. See the section: Repairing Loose Front on Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens. Well worn but functional.

    4. ID #4 (SN: US16591854): Fully functional.

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Disassembly

    Referring to the repair manual is probably the simplest way to do a systematic disassembly of this lens down to just above the level of the alunimum Zoom Barrel with the tracks controlling the motion of all 3 lens clusters, and which houses the middle Lens Cluster (with AR). The manual does not go below this point. If putting it back together isn't a requirement, just removing all visible screws along with unsoldering or cutting a few wires and pulling flex cables from their connectors will accomplish the task. ;-) However, there is a specific order in which some parts are removed to really get to the bottom of things without trauma.

    Though I do not have an intact sacrificial lens at present, I will be hunting for one. Of if someone would like to donate one, it will be immortalized. ;-) So, there should be more to come soon.

    It is best to set each subassembly aside along with its screws in a plastic bag or some other safe place. There are at least a half dozen different size/types of screws and using the wrong one can strip a threaded hole. Note: An attempt was made to use names from the repair manual, so some may seem strange. ;-)

    CAUTION: Do NOT remove the back lens group (called the "4th lens-G unit" in the manual) if intending to reassemble the lens into a fully to-spec state unless closeup photos are taken so that can be replaced in exactly the same position. Else it may require Nikon to align it for only 5 times the cost of a replacement lens. It is secured with 3 screws and washers, sealed with something like Loctite™.

    Back of lens

    1. Set zoom to 55mm.

    2. Remove the single securing the Switch Plate, flip it out, and pull the flex cable out of the connector. There is no lock.

    3. Unsolder the Ground Wire from the solder pad on the flex cable. If no soldering equipment or expertise is available, it is also possible to remove the screw securing the Gound Contact assembly from the Outer shell but putting it back in place is challenging and risks breaking the wire. Soldering would be needed repair that.

    4. Remove the 3 small screws around the periphery of the Inner Ring and it.

    5. Remove the 2 securing the Camera Contacts and gently move it toward the center of the lens.

    6. Remove the 3 large screws securing the Bayonet Mount and remove it along with the Spacer Ring(s) taking care not to snag the Camera Contacts.

    7. Remove the Fixed Tube. Set it aside along with the bayonet parts.

    8. Remove the Camera Contacts flex cable by pulling straight out from the connector. There is no lock. Set it aside.

    9. Disconnect the remaining flex cables (except for the white cable) from the CPU PCB. They all pull straight up or out with no locking tabs.

    10. Remove the screw securing the CPU PCB.

    11. Lift the locking lever on the connector and remove the white flex cable.

    Front of lens

    1. Slip a thin piece of plastic under the model label and lift the edge, then work it around to remove the label entirely without scratching the glass. With care it should be possible to put the label back later with at most minimal evidence of trauma.

    2. There are two holes or slots near the edge of the Front Lens Cluster for a spanner wrench. But it is usually not that tight so a thin tool should suffice toe be able to unscrew it counterclockwise (CCW). Set it aside in a safe place.

    3. Remove the Rubber Grip by slipping a thin piece of plastic underneath the front edge so the entire thing can be pulled off. After long use it may stick to the Zoom Barrel from congealed finger oil ;-) but there is no adhesive.

    4. Remove the polyester tape securing the Trim Ring to the Zoom Barrel and remove it.

    5. Set zoom to 55mm.

    6. Set the A/M Focus Switch to M and rotate the Filter Ring clockwise (CW) to the fully extended position. Set the switch back to A to lock the Filter Ring.

    7. The two fork tines of the Segment Gear Tube should be just barely extending into the slots in the Filter Ring. GENTLY spread the fork tines apart so the Filter Ring can be rotated further CW and removed.

    More to come.

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Reassembly (Coming Someday)

    ;-)

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Dissection

    The preliminary set of photos can be found in Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Dissection Web Album. There is no complete dissection yet but it has most of the relevant photos cobbled together from what's left of the 2 "parts" lenses and a nice intact specimen, as well as the stock photos, the optical architecture, and how the lens groups move with zoom. Some key bits are missing like the Fixed Shell since neither of the parts lenses had one. In addition, various flex cables were missing or damaged. And I wasn't thinking about a detailed dissection when disassembling them. So a sacrificial lens will need to be acquired. If someone would like to donate one, it will be immortalized. ;-) These photos were taken using one of my trusty $10 D70s with the repaired VR lens (see the next section) using a pair of 75W incandescent lamps (with the D70 White Balance set to Incandescent) in place of the LED bulbs and fill flash used for most of the previous shoots. Using the incandescent lamps seemed to require less color correction. Most of the photos to follow will as well.

    Repairing Loose Front on Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens

    A hard whack to the front of this (and other similar) lenses can fracture one or more of the plastic rollers that guide the front portion of the lens including the Focus Ring and Focus Barrel. The symptoms will be that the front of the lens is very loose but the lens may be somewhat functional, though with erratic autofocus and the quality of the pictures taken with it will be hit or miss. The seller of the lens used for this repair described the issue as "front impact damage", which is accurate.

    The parts are shown in: Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Focus/Zoom Guide. The stud with the rollers is secured through the Fixed Barrel of the lens with the screw on the left with the offending roller missing as will likely be the case with this failure. Both are present next to it, and only a roller on the right. I'm calling them "rollers" though it's not clear if they are intended to actually rotate or just slide within the focus and zoom tracks. When fractured, it's likely that some pieces will break free and float around in the lens interior or perhaps fall out through the back.

    This is among the simplest lens repairs not even requiring any precision tools. That is, assuming replacements for the broken plastic pieces are available - most likely only from a sacrificial AF-S 18-55mm VR lens or other similar small lens (though that is probably not very likely given Nikon's tendency to reinvent everything with each new model). In principle, it is possible to fabricate replacements but they probably won't be found on eBay or anywhere else at affordable prices or at all. Also note that there are 2 sizes of these roller thingies on the same shafts in this lens - the larger ones control movement of the Inner Barrel with Lens Groups 4-8 while the smaller size (relevant here) is for Focus. They are not interchangeable. The smaller size is the one needed here unless both are broken. But the procedure for replacing the larger ones may be considerably more involved as they will be captive by the Focus Barrel and likely requires much more extensive and tricky disassembly.

    The broken pieces are at the front of the lens and the disassembly is relatively low risk. For some of this, the repair manual (above) provides help with photographs, but it goes much deeper than needed for this repair, and getting carried away removing stuff can ruin your entire day. It is also NOT even necessary to remove the lens cap, which should be left in place to protect the front glass.

    1. Remove the Rubber Grip by carefully lifting the front edge and pulling it off. If the rubber is healthy, it will not become deformed. But on really old lenses the rubber may be somewhat dead and flabby and may not recover its original dimensions, at least not quickly.

    2. Remove the strip of polyester tape securing the Trim Ring to the Zoom Barrel. It may be possible to re-use this but don't count on it.

    3. Remove the Trim Ring.

    4. Set the AF A/M switch to "M" and rotate the Focus Ring clockwise to the fully extended position. Set the AF A/M switch to "A" so it stays there.

    5. Set zoom to the 55mm position.

    6. Check the position of the two tips of the plastic "fork" that engage the outside of the Filter Ring. They should be barely on the Filter Ring (<1/8th inch). It should then be possible to CAREFULLY spread them apart just enough so the Focus Ring can be rotated further clockwise and removed. If they are any further forward, confirm that the Filter Ring is at the fully extended (closeup) position (fully clockwise) and zoom is at 55mm. Otherwise there is a risk of them breaking when spread apart.

    7. Set zoom to the 18mm position to retract the inner lens groups and make the trouble areas accessible inside the Fixed Barrel, which is part of the main structure of the lens.

      Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Missing Guide Rollers shows a view inside the Zoom Barrel where 2 of the rollers are missing from the ridged studs.

    8. There may be some bits of the broken plastic rollers still on the ridged metal post(s) or bouncing around inside the lens. Shake them out and try to account for all the pieces. But it's possible some or all have escaped out the back.

    9. Using a pair of tweezers, gently slip the replacement roller(s) over the ridged metal post(s). They should be flush with the Focus Barrel inner surface.

    10. Once all the rollers are in place, immediately replace the Focus Ring by slipping it into the helical grooves and rotating it counterclockwise. It should only go in at the correct orientation and move without resistance until it snaps in place. At that point, "Nikon" on the model decal should be near the top of the lens. If it doesn't move easily, one or more of the rollers may be poking out, some roller fragments may still be present, or it's at the wrong (120 degree) orientation - don't force it. Or something else is damaged. Once confirmed, it would be worth adding your own reference marks to identify the correct orientation of the filter ring if future repairs are required.

    11. Check the stability of the focus ring. It should not wobble noticeably. Test that focus and zoom move smoothly and can be adjusted normally over their entire range.

    12. The lens can be mounted on a camera at this point to confirm that it is happy. Test it a all settings of zoom and focus. If focus cannot be achieved close and far at one or the other end of zoom or anywhere, the orientation is probably incorrect. Recheck it!

      CAUTION: Do the initial testing over a padded surface in case the orientation of the Filter ring is not correct as it may pop off during autofocusing and fall out. That has happened a couple of times fortunately resulting in only minor cosmetic damage but it could be much worse. ;-(

    13. The remaining steps are the reverse of the disassembly. If the polyester tape cannot be reused, Kapton electrical insulating tape or even thin plastic packing tape should be satisfactory since the Trim Ring is mostly cosmetic ane doesn't serve any critical function, and is under little stress. Clean the area where the tape goes both on the Zoom Barrel and Trim Ring before replacing it. Take care not to dislodge the padded strip on the inner surface of the Trim Ring which helps to keep out dust. If a portion needs to be reattached, it and the surface of the ring should be cleaned with degreaser to remove residual oil and/or grease.

    One mystery with the lens (ID #3) used for this description is that there were no signs of broken roller bits inside and the lens does not appear to have been opened previously. So they may still be inside somewhere waiting to cause havoc or fell out the back. There was a fair amount of dust inside which says something about the lack of decent seals on these things. ;( ;-)

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens

    I have not found a repair manual or even an exploded parts diagram for this lens, only the boring user manual. If anyone has one, please contact me via the Sci.Electronics.Repair FAQ Email Links Page. The differences between the VR and VR II lenses are fairly significant so the repair manual for the VR version may not even be useful for the gross anatomy. ;-)

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Description

    This is the newer version of the AF-S DX 18-55mm f/3.5-5.6G VR zoom lens. It has a similar (but not identical) optical design but is smaller and lighter with a lock button so it collapses for storage like the AF-P lens, below. It uses the same SWM technology so it was not immediately clear how this could be possible based on size. It is about 15 percent smaller in diameter and slightly shorter. It is barely larger than the AF-P lens and is almost 1/2 inch shorter when zoomed to 55 mm. I originally thought the AF-S VR II might use a worm gear drive like the AF-P lens but with the SWM rather than a stepper. However, that would not explain how the focus ring can move on its own during autofocus operation since the AF-P uses a "fly by wire" control system for manual focus. Hmmmm. ;-)

    Out of curiosity, I puchased a supposedly defective sample of this lens where the trim ring had popped off as shown in: Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens with Loose Trim Ring. It looked bad and for that reason the price was right, but was easily repaired. See the section: Repairing Loose Trim Ring on Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens.

    While searching for another one to dissect, measurements of the SWM frequency provided a clue as to the design changes. A 6 turn sense coil was placed under the lens, which as before was determined to be the optimal location for a strong signal, probably in close proximity to the ferrite HV transformer(s). Rather than 77 kHz as in the original AF-S lens, the frequency for the AF-S II is around 290 kHz (!!) which was originally assumed to indicate a much smaller motor (though this turns out not to be the case, more below).

    When the focus ring is moving, the pulse width may be up to around 700 ns. But there is still a detectable very stable ~100 ns spike at the same frequency with similar amplitude for several seconds after the camera has beeped indicating that optimal focus has been achieved, not only while the focus ring is moving. So it is likely from the same source and not just pickup from the logic, perhaps a sort of dither to minimize stiction in the mechanism between focus operations.

    But it turns out that the SWM itself appears to be physically identical in both lenses. And the gear reduction is also similar. Then I thought perhaps the higher frequency was selected to be able to smaller magnetic components, but this also turns out not to be the case. So my conclusion now is that the higher frequency may have been selected primarily because it permits faster focusing or because of complaints from local bats. ;-)

    The physical size reduction of the VR II lens is thus accomplished by mostly clever packaging. ;-)

    Here is a summary of the Nikkor 18-55mm AF-S DX f/3.5-5.6G VR II lenses I've acquired so far:

    1. ID #1 (SN: 20750167): The lens with the loose trim ring, above, repaired with tape. The good aperture tang was transferred to ID #3 and replaced with the one from ID #6 (the dissected lens).

    2. ID #2 (SN: 22341241): Then I bought another supposedly broken AF-S VR II lens also to dissect if it could not be repaired easily. But nothing was found to be wrong with it except for some crud on the base that looked bad but was easily cleaned up. Zoom may not be quite as smooth as for some other similar lenses but that doesn't seem to affect anything and could just be a sample-to-sample variation. Darn, another working lens. I hate it when that happens. ;-)

    3. ID #3 (SN: 22643651): The next supposedly faulty AF-S VR II lens was indeed defective. The plastic tang that operates the aperture (iris diaphragm) broke near its base, and engages only when zoom is below around 24 mm. Discombobulating an otherwise good lens with a known straightforward repair - likely with no hope of reassembly - would be a shame. So it would be better to find a totally smashed lens with that part intact. But the bayonet mounts were swapped between this lens and the one with the re-taped front ring (ID #1), so ID #2 and ID #3 are totally good now. ID #1 has the tape and broken tang.

    4. ID #4 (SN: 22017590): Another supposedly faulty VR II lens was also definitely defective, working only over a part of the focus range. And it's absolutely perfect otherwise. See the section: Autofocus only Works over Limited Range on Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens. I'm still hoping to dissect a certifiably dead lens first to become familiar with the innards before attempting repair of this one. But since the aperture tang is fine, that part could be transferred to taped ID #1 which now has the broken tang from ID #3.

    5. ID #5 (SN: 23353989): Fully functional but that is how it was described, so won't help in the search. ;( ;-)

    6. ID #6 (SN: 24030966): This is bad enough to go inside (at least somewhat) and possibly totally dreadful. ;-) It is not recognized by a camera and there were white deposits on the rubber focus grip though no where else on the exterior. There is no visible evidence of serious water damage or anything like that and the electrical contacts show continuity to internal components. But there is definite contamination on at least one of the inner surfaces of the rear lens element(s), if those are removed for cleaning, recalibration may be required by Nikon equipment and proprietary software, this is probably similar. Therefore it would almost certainly not stand a chance of meeting factory specs even if functionality could be restored. The only downside to dissection is that after cleaning the rubber, it looks quite nice with the only blemish being some mottling on the silver stripe of the trim ring. ;-) But its destiny is sealed.

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Disassembly

    With care, the following procedure may be used to take one of these lenses apart in a (mostly) reversible manner. The only slight exceptions will be a few places where double-sided tape or adhesive is used to secure cables or connectors and they may need to be replaced.

    Note that for the following, the Fixed Barrel, Fixed Shell, Metal Ring/Shims/Insulator/Spacer, and Bayonet Mount are all one structure secured from the back by the 3 larger screws. The Zoom Barrel rotates around the this and the lens clusters/groups move with respect to it.

    Please refer to the Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Dissection Web Album and Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Parts Identification. Not everything is labeled but these should be a start.

    Set aside each set of screws with their respective parts as there are several different size and length screws involved here.

    This is from memory so some details may be a bit fuzzy. ;( ;-)

    It is highly recommended that match marks be added at each step where a major piece is removed as the quasi-3-fold symmetry can greatly confuse things. The only part with true 3-fold symmetry may be the Trim Ring. ;-) All the others can be put together correctly or at all with only one specific orientation. And this is a lens so take photos at each step. ;-)

    1. Remove the 3 screws securing the small ring in the center of the bayonet mount and take it off.

    2. Remove the 2 screws securing the Camera Contacts (Ball Strip).

    3. Remove the 3 screws securing the Bayonet Mount and *carefully* take it off without stressing the cable. The Camera Contacts will remain attached to PCB1 for now.

    4. Lift off the thick metal ring, thin shim ring(s), and plastic spacer/insulator ring.

    5. The 7th,8th lens groups (back lens cluster) should NOT be removed unless absolutely necessary (for example to clean the front surface of the 7th lens group or the back surface of the 6th lens group). Their position are critical to lens performance and may not be absolutely centered. Specialized instruments and proprietary Nikon software are required to fine tune the position if it gets messed up. Thus this must be restored to where it was originally upon reassembly, so take closeups BEFORE loosening the screws as a position reference. Having said that, to get at the screws, the protective plastic cap must be popped off - it is held in place with double-sticky tape or something similar. There are tiny black plastic washers under the screw heads which presumably serve some important purpose. ;-)

    6. Carefully remove the 4 flex cables from their connectors on the top of PCB1. They pull off with no locking levers. Some have tiny holes into which a thin (but NOT sharp) tool can be inserted to assist in removal. The largest one going to PCB2 has no hole but a thin tool like an unbent paper clip or tooth pick can be inserted under it to aid in pulling it free of PCB1 or PCB2. Two other cables (Camera Contacts and Gyros) are under PCB1 so wait until the next step for them.

    7. Remove the two screws securing PCB1 and gently lift it up, removing the 2 remaining connectors to free it from the Fixed Barrel. A black grounding wire will need to be unsoldered from the PCB. That is the only unsoldering required during disassembly. If unable to deal with solder, leave it attached to PCB1 and set them aside together.

    8. Remove the 2 screws securing the Spring Ground Contact (over the SWM) and its wire. Otherwise, it will interfere with removal of other parts. It also limits Zoom Barrel rotation to 55 which will prevent further disassembly of the main lens barrels and other components.

    9. Slide a thin piece of plastic under the model label on the front of the lens so it can be pulled off. DO NOT use metal as it may scratch the lens. There are small indents around the perimeter of the label where something pointy can be slipped under the ring from the outside to aid in this.

    10. The front lens cluster with the 1st-3rd lens groups can now be removed. There are holes for a spanner wrench for the purpose but it typically isn't that tight so a pointy tool in one of them and care is all that is needed to rotate the locking ring counterclockwise.

      Note that this step isn't absolutely necessary unless replacing it or desiring access to the VR assembly.

    11. Lift up an edge of the rubber grip and pull it off. This can be done without damaging it.

    12. Peel off the strip of clear Gorrila tape securing the trim ring to the Zoom Barrel.

    13. The trim ring can be pulled off.

    14. Rotate the Zoom Barrel to beyond the "55" position which should cause the Fixed Shell to pop off of the Fixed Barrel. As it comes free, the metal Focus A/M switch fork will probably take the small black SWM gear with it. Regardless, remove that gear along with the long focus gear and set them aside so they don't just go flying off to oblivion when you're not paying attention. DO NOT stress the SWM Gear or shaft as it's plastic and can break easily. ;(

    15. It should be possible to slide the Fixed Barrel ~1 inch out of the Zoom Barrel.

    16. The SWM is now accessible and may be taken out if desired by removing 2 screws securing the grounding spring assembly, the 2 screws securing the SWM itself, and detaching its connector.

    17. PCB2 (SWM drive) may be taken off by removing 2 screws. Don't lose the short flex cable that connected it to PCB1.

    18. Remove the single screw securing the Focus Encoder flex cable. DO NOT remove the flex cable from the metal piece.

    19. The Focus Assembly including the Focus Encoder can be pulled off along with the Zoom Shell. Take care not to damage the Focus Encoder Brush as well as the Focus Tachometer magnetic read head.

    20. The Focus Assembly can be separated from the Zoom Shell if desired by removing the 3 screws around its perimeter. This exposes the Focus Encoder strip, brushes, magnetic tachometer stip, and read head. If the flex cable is stuck somewhere, it can be unstuck. ;-)

      CAUTION: The magnetic tachometer read head on the focus assembly is on a miniature metal spring suspension so that it is in contact with the magnetic strip - see the dissection photos. It is easily bent and damaged. Take note of its location and be careful when handling the focus assembly. It can usually be repaired if not deformed too badly. Also, magnetized tools in close proximity to the magnetic strip could erase the magnetic pattern rendering it and the lens useless. There are YouTube videos involving replacing that strip on other lenses but you really don't want to go there. :( ;-) A sufficiently powerful magnet (or tape head demagnetizer) near the lens could conceivably do it as well.

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Resassembly

    This is actually not quite as involved as I originally thought. (And that probably applies to the AF-P and other lenses as well.) The quasi-3-fold symmetry of these lenses makes it more of a challenge as there is only one orientation for most parts that is correct. But most often it isn't quite 120 degrees and screws will only line up with holes in one of the three possible orientations. The Fixed Shell, Fixed Barrel, Zoom Shell, Zoom Barrel, and Focus Assembly all need to line up just right for it to go together properly. The good news is that so far, the half dozen or so flex cables have survived without serious trauma (fingers crossed). They are tougher than originally thought (though various parts lenses on eBay have shown some to be torn). It's usually sufficient to be aware of the cables. Pulling things apart without realizing a cable is involved is where bad things happen.

    If match marks were made during disassembly, this will be a much more straightforward. If not, refer to the dissection photos.

    Please refer to the Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Dissection Web Album and Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Parts Identification. Not everything is labeled but these should be a start.

    In all the fussing, the plastic mounting post for the SWM Gear broke off at its base. ;-( Repairing that was a pain but appears to have been successful: A slightly under-size hole was drilled in the stump and then the post was press-fit back in place. For the OCD types, adding a bit of non-softening plastic adhesive would have probably been worthwhile. It's a fraction of an inch shorter than the original but should be good enough for government work, especially considering that I have no intention of actually using this lens - ever!

    Three 2-56 nuts and washers will be required during reassembly which are not part of the lens. These substitute for the metal rings etc. and Bayonet Mount to secure the Fixed Barrel and Fixed Shell with similar thickness until the Bayonet Mount is installed.

    If individual parts like the SWM or PCB2 were removed during disassembly, additonal steps may be required, but they should be self-evident, intuitively obvious, or both. ;-)

    1. Slide the Focus Assembly into the Zoom Shell and secure it with 3 screws. Slip the flex cable for the Focus Encoder and Tachometer through the slot in the between them taking care not to damage it. There is only one of the three orientations where these will mate properly.

    2. Slip this combined unit into the Zoom Barrel with the small dot on the Lens Hood Mount just beyond the 55 mark. The two pegs on the Fixed Barrel and plastic protrusion on the Zoom Shell should slip easily into the pair of tracks on the Zoom Barrel but will not go further.

    3. Gently pull the Fixed Barrel out so it extends as far back as possible.

    4. Replace the Zoom Brush using its screw.

    5. Replace the Focus Gear in the hole in the Fixed shell so that it extends and engages the rotating part of the focus assembly. If it doesn't reach, push the Fixed Barrel in very slightly.

    6. Insert the SWM Gear into the A/M fork on the Fixed Shell. The top has a ridge that will stay in the fork.

    7. Carefully position the Fixed Shell on the Zoom Barrel so the large dot lines up with the small dot on the Lens Hood Mount and just beyond the "55" on the Zoom Barrel. The Fixed Shell and Zoom Barrel should seat flush against each-other as they would be normally. (Later it will lock in place when toward "55".) Take care to avoid damage to the Zoom Brush. The 3 Bayonet Mount holes should line up with the mating holes in the Fixed Barrel and be touching or almost touching, but probably not fully seated.

    8. Place a 2-56 nut and 2-56 washer on each of the screws that attach the Fixed Shell to the Fixed Barrel. Gently thread each of these through the Fixed Shell into their mating holes on the Fixed Barrel to pull them together while attempting to turn the Zoom Barrel. Do not force anything. It should now be possible to rotate the Zoom Barrel normally to the Locked position. The nut and washer are temporary until the remaining parts of the back of the lens are replaced. If the Fixed Shell and Fixed Barrel are too far apart for the screws threads to engage, use only the washers until they can get a solid grip all around and then back them out and add the nuts. The screws should not bottom in the holes. Damage to these threads would be bad since the 3 screws secure the lens to the camera body.

      If the Zoom Barrel doesn't turn easily, use a thin piece of plastic to depress the (now hidden) pegs for lens groups 4,5,6 (middle lens cluster) just enough so they can slip into their tracks inside the Fixed Barrel while gently twisting the entire combined unit counterclockwise. Don't force anything. Didn't I say that already? ;-)

    9. It should now be possible to rotate the Zoom Barrel to the Locked position. Do NOT squeeze the Fixed Shell. Without the Bayonet Mount and associated parts being secured to the Fixed Shell, it will distort making it hard to rotate the Zoom Barrel. There are no precision roller bearings. ;-)

    10. Install the Spring Ground Contact using its 2 screws. This also serves as the zoom stop at the 55-end.

      See: Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Final Reassembly. The nuts and washers substitute for the Bayonet Mount and associated parts prior to their installation. The photos show the lens in the Locked position.

    11. The Zoom Barrel should now rotate normally between Locked and 55 but no further with each part of the lens moving as it should. The screws, nuts, and washers installed above can probably be removed safely now since the Zoom Barrel will not be able to rotate past 55 where it could detach, but there is no harm in leaving them in place until final assembly.

    12. Install the Trim Ring so it seats in the six slots. The Trim Ring has 3-fold symettry so it will mate in 3 possible orientation and they are all equivalent. Secure it with the 1/4 inch gorilla-strength tape. ;-) I used Kapton electronic insulating tape but that is probably not optimal. Press the tape in place all around particularly on the 6 tabs.

    13. Slip the Rubber Grip over the front of the lens so it lines up with the Lock Button.

    14. Replace the Front Lens Cluster assembly by rotating it clockwise until it seats against the Focus Assembly. It should be snug but do not overtighten.

    15. Replace the model label. For reference, the left edge of the "D" in "DX" should line up with the dot on the Lens Hood Mount. This is really important! ;-)

    16. Attach the cable from the Camera (CPU) Contacts to the large white connector on the underside (actually the front) of PCB1 paying attention to orientation so the contact unit is oriented correctly. It presses in with no locking lever.

    17. Similarly, attach the Gyro Cable to the small connector on the underside of PCB1

    18. Install PCB1 and secure it with its 2 screws. Take care that none of the protruding flex cables get stuck under the PCB.

    19. Install each of the remaining cables. They press in place with no locking levers. Their locations and orientations should be self evident. ;-) On some, there is a small hole near the end of the cable that can be grabbed by a thin (but NOT sharp) tool to aid in insertion.

    20. Resolder the ground wire from the Spring Ground Contact to the pad on PCB1 if removed during disassembly. Make sure it is routed away from the center where it might get caught during zoom operation.

    21. Remove the 2-56 nuts and washers. DO NOT rotate the Zoom Barrel or pull on the Fixed Shell until the entire thing is secured to the Bayonet Mount.

      The right photo in Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Final Reassembly shows its appearance now.

    22. Replace the plastic insulating ring, shim(s), metal ring, and Bayonet Mount. Slide the Aperture Tang into the Aperture Slot inside the lens and secure the Bayonet Mount and related parts using the 3 large screws.

    23. Confirm that the aperture range goes from min to max. (This shouldn't have changed unless parts were swapped from another lens.)

    24. Carefully position the CPU Contact Block in the Bayonet Mount and secure it with its 2 screws.

    25. Replace the Inner Ring and secure it with its 3 screws.

    That's it! With care, match marks, photos, attention to detail, perseverance, and a bit of luck, the entire disassembly and reassembly process was not impossible and a learning experience. Now the lens should work perfectly if it did originally or if broken parts were replaced. If the lens survived and you survived, the next one will be easier. After the 17th iteration, it will seem totally trivial. ;-)

    While the details for other lenses will differ, the general procedures will have a lot in common and doing this first with a lens like the AF-S DX 18-55mm VR II should provide good experience before tackling a larger expensive one. The key to success is understanding how the motion of the lens clusters is "programmed" by the tracks inside the Fixed Barrel and then being able to install them correctly during reassembly.

    Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Dissection Web Album

    All of the photos are available as a Web Album at Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR_II Zoom Lens Dissection Web Album, which will be a more-or-less step-by-step disassembly like that of the camera dissections. So from start to finish it goes from the fully intact lens to the naked parts. ;-) Most photos were taken with a D70 using lens #5 except for a few of the closeups using the Micro Nikkor AF-S DX 40 mm f/2.8G. The original mostly white backgrounds have been allowed to remain for some of the photos since that gives them more of an authentic look. Where they couldn't be bleached adequately via exposure or gamma/contrast adjustment - or just for consistency - the inPixio On-Line Background Removal Tool was used.

    Most of the photos are now present in the Web Album. Except for the first 2 stock photos, all are of lens #6 except for the few showing the back of the lens with the bayonet mount and associated parts removed.

    Other than the front of the 7th lens group and back of the 6th lens group which has some mottling (which was easily removed with 90% isopropyl alcohol), the interior including the PCBs, connectors, SWM, gears, and everything appear to be pristine with no evidence that contamination caused the lens's failure. So perhaps it was zapped by static. And yes I violated my recommendattion to not remove the 7th,8th lens groups but there is really no intention to put this lens back in service.

    Some conclusions so far: The VR II is somewhat cost reduced but in a good way. ;-) For example, only one wire needs to be unsoldered to totally disassemble it to the level of major components. Most flex cables plug into the CPU PCB (PCB1) and are the push-in type with locking levers to break. Many have a small hole near the end of the cable for a thin instrument to aid in removal. There is a minimal number of pieces of double sticky tape or adhesive which would need to be replaced if reassembled.

    Focus implementation is generally similar to that of the AF-S VR lens but the SWM gear train is part of the main structure and NOT a separate assembly. The tachometer and its gears are gone. Speed sensing has been implemented with a magnetic strip as in some other AF-S lenses. The good news is that the SWM itself and the two remaining gears are replaceable without major disassembly.

    The focus encoder coding is of course different than the one in the AF-S VR and all other lenses I've checked. But is that a surprise? ;-) See Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Focus Encoder Coding. This encoder has 6 data bits with 22 states. The spacing almost makes sense being fairly similar in the central region and further apart near the ends. The extra tracks in the photo are pass-through for the magnetic read head.

    The Zoom Encoder does NOT run axially as in the the AF-P 18-55mm VR lens (which has a similar lock button). It runs around the perimeter of the inner surface of the Fixed Shell and is extended to cover the locked area with a constant code. (Take care not to damage the brushes if the Fixed Shell needs to be reomoved.) At the location where it becomes unlocked, there is a very small length where the common conductor extends to the next one over, but that would not result in a different code, so its purpose is mystery. See Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Zoom Encoder Coding. This encoder has 8 data bits with 36 active states and the locked state. In the main portion of the active zoom region, their spacing is similar but not precisely the same. For the locked region, the code is a constant 00110001. Note the 8 data bits rather than 6 data bits for all the other lenses analyzed so far. Yet again, we have a change to the encoder coding and now even the number of bits for no fathomable reason. 6 bits would be plenty. It almost seems as though the designers of these lenses (1) are not privy to documentation on other lenses, (2) have a serious case of NDITD (Not Developed In This Department) syndrome, (3) never heard of lookup tables, (4) are smoke'n sump'n, or (5) all of the above. It makes no sense whatsoever.

    The VR II VR assembly has changed slightly compared to the AF-S VR (I) lens. It is smaller and similar (but not identical) to the one in the AF-P VR lens. As with that one, the Hall sensors are gone so changes in the VR lens group position must be sensed in some other way.

    The state of affairs as depicted in the Web Album is about as far as I intend to go in the disassembly. There are still a few individual parts that have not be removed or reduced to their individual pieces, usually due to issues of reversibility of the procedures, but all key sub-assemblies have been removed and documented. This applies for example to the SWM and VR assembly. There is little point to taking them to bits as that has been done for the 18-55mm AF-S VR and AF-P VR lenses, and they are similar. While nothing had been damaged, restoring the lens to its original condition is probably not going to happen. While there is a small probability that simply reseating the connectors will have cured the "not recognized by the camera syndrome", I'm probably not that determined to find out. And if the CPU PCB (PCB1) is dead, swapping in one from another lens will not work well as VR parameters and other settings need to be optimized for each specific lens using the custom specialized Nikon test instruments and software. However, physically putting it back together seems possible without having mastered a 27 level Rubik's Cube though there are a couple of steps that could be dicey like replacing the Fixed Shell.

    Explanations of the dissection photos will be forthcoming so stay tuned. ;-)

    Parts Naming

    (Some or most of these may not agree with how Nikon sees it as no internal diagrams or parts lists are available.)

    And should anyone actually read this before the warranty on the Universe expires and has specific questions or requests, I may be contacted via the Sci.Electronics.Repair FAQ Email Links Page.

    Repairing Loose Trim Ring on Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens

    Both the AF-S VR and AF-S VR II lenses have a trim ring at the front with a silver stripe. Its main purpose appears to help keep dust out of the mechanism and perhaps stabilize the focus barrel. So replacing it may not be essential but is worthwhile.

    The trim ring is held in place only with a strip of ~1/4 inch tape wrapped around the entire lens. But while the original AF-S VR lens has a decent width area around its entire perimeter for the tape, the AF-S VR II trim ring only has six very narrow tabs that after awhile (or from an impact) can come loose as was the case with the first AF-S VR II lens I acquired (ID #1). See Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens with Loose Trim Ring. It looked really bad and the lens was destined for dissection if repair was not practical. But fixing it simply required removing the rubber grip by lifting it away from the body pulling it off, and then replacing the tape. But Nikon must use tape with super-strong adhesive as ordinary tape probably won't hold for long. So far though it's been behaving with just some Kapton tape, and many of the photos for the camera dissections have been shot using this lens. It might also be possible to use a few dabs of adhesive like 5 Minute Epoxy or industrial strength rubber cement between the trim ring and the barrel it seats against, but this has not be attempted - yet.

    And the racing stripe (which is purely cosmetic) is just a length of really thin metal-coated tape which often detaches at one end. Or corrode as in the case of the lens ID #6 used for the dissection. It can usually just be peeled off if desired, which is a lot easier than attempting to neatly glue it back in place.

    Replacing the Bayonet Mount Parts on Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens

    A sharp WHACK or overzealously attempting to attach the lens if not properly engaged can result in fracture of the cheesy plastic bayonet mount. I've also seen one of these lenses with most of the plastic aperture tang inside the lens (that actually moves the iris diaphragm) broken off and missing. (It's not even clear how that can happen.) Assuming replacement parts are available, these and similar issues require the same disassembly steps and are among the few repairs of these sorts of lenses that are possible without a great deal of prior experience.

    This procedure may apply to some other Nikon lenses. But specifically NOT to the similar AF-P lens where removing the CPU contact block screws results in the individual contacts popping out all over the place. ;-(

    A #00 or #000 Philips screwdriver is required for the 3 sizes/types of teeny screws:

    1. Remove 3 screws securing the inner ring to the bayonet mount. These screws have the smallest heads. It should then be possible to pop off the inner ring.

    2. Remove 2 screws, one on either side of the CPU contact block securing it to the bayonet mount. These are very short machine screws.

    3. CAREFULLY work the CPU Contact Block around so it can be freed from the bayonet mount but remain attached via the orange flex cable. It may need to be tilted or angled but there should be enough slack in the cable. DO NOT pull or stress anything! At the very least, the cable can pull free of the connector, which will then require more extensive disassembly of the lens to reattach it. The cable could also tear. ;-(

    4. Remove 3 screws near the edge of the bayonet mount securing it to the lens housing, and can now be removed without disturbing the CPU contact block.

      See Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Bayonet Parts.

      CAUTION: DO NOT attempt to rotate the Zoom Barrel with these screws removed as the whole thing can come apart requiring an order of magnitude greater level of skill to reassemble. Specifically, the Fixed Shell may come free of the Fixed Barrel taking the SWM Gear with it and possibly damaging the Zoom Brush as well as the Focus Assembly and Zoom Barrel popping out the front.

    Individual parts of the bayonet mount can now be replaced if necessary, though this will at least one level up of fiddlyness. ;-)

    Reassemble in reverse order. And don't force anything! All of these are tiny screws so stripping holes is possible. When reinstalling the bayonet mount, carefully insert the aperture tang straight into the plastic receptacle that moves the iris diaphrapm. Unless the bayonet mount is replaced without changes, the setting of the aperture tang may need to be adjusted. It's secured with 2 screws and sealer. I do not know what the official procedure is, but in lieu of that, make sure the aperture tab (that's activated by the camera) just touches the the edge of the cutaway in the inner ring. Then after securing the bayonet mount, confirm that the tab moves smoothly by hand and the aperture goes through its entire range.

    Autofocus only Works Over Limited Range on Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens

    The following most likely applies to other AF-S lenses and in part to others. A Web search will turn up cases of generally similar autofocus problems. For example: Focus Hunting Problem in AF-S Nikkor 24-70mm 1:2.8 G ED Zoom Lens and Nikon Lens repair: Broken Autofocus on a AF Nikkor 28-70mm Zoom Lens. These both involved a dirty or damaged encoder to be the cause, similar to my conclusions (below) based on the symptoms prior to internal examination of this lens and before finding these videos. Problems like this do tend to have simple causes.

    This lens (Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II ID #4) works perfectly in all respects from its closest focus to around 2 feet. It will go back and forth between those distances all day without issues. But beyond there, it will never move the focus ring to get closer, and at some point it will jam against the end-stop beyond infinity.

    This is a works in progress but here are some observations:

    My current hypothesis is that the encoder that reads focus position is either not working correctly or has perhaps become disconnected. So the lens's microbrain is getting confused, poor thing. ;( ;-) Among other things it's not being programmed to provide the necessary torque to focus in from near infinity, and it's overshooting infinity, hitting the end-stop and getting really stuck there. Monitoring of the SWM waveform appears to show that it is trying but almost certainly attempting to rotate the focus ring in the wrong direction. With the high gear ratio, it should have no problem backing away. The only way to unstick it if jammed is to flip the A/M switch back and forth. However, even if not jammed, it will still not focus in from more than around 3 feet to infinity. It will focus reliably from the closest spec'd distance to around 2 feet, though it may overshoot dramatically but doesn't jam. All these lenses sometimes overshoot especially if there little detail in the focus zone.

    Since there is a definite boundary beyond where it screws up, this would appear to rule out an SWM or gear train problem. The SWM rotor and all gears except the one on the focus ring itself go through multiple revolutions over the focus range. The rotor of the SWM itself goes through ~2.75 revolutions for each revolution of the focus ring drive gear and that goes through nearly 2 complete revolutions to move the focus ring from end-to-end.

    So this is probably a control problem. The only inputs to the microbrain are the tachometer (a magnetic strip with read head) and the focus encoder (which senses the absolute position of the focus ring). It's possible the magnetic pattern the tachometer uses has been partially erased, but the most likely cause is the focus encoder: Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Focus Encoder Coding with the bits color coded and labeled with the binary value at each position. More on these encoders can be found in the section: Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens. But interestingly, the focus encoder in the Nikon AF-S DX Nikkor 18-70mm f/3.5-4.5G ED IF Zoom Lens also has 4 conductive strips and 6 bits, but the coding differs, which really doesn't make any sense unless each new Nikon designer is required to change something as a test. ;-)

    If you're not totally confused, you weren't paying attention. ;-) But to reiterate: It is most likely that the focus encoder is either feeding bad readings to the microcomputer or they are being misinterpreted.

    No doubt disassembly of this lens will be required at some point, to satisfy my curiosity if nothing else. Hopefully the problem will be something obvious like a damaged focus encoder brush, loose connector, or some dirt or soda residue on the encoder strip. ;-) However, based on the dissections (See above), this requires fairly significant surgery, so it may be postponed until Major Medical insurance coverage is available. ;-(

    Repairing Broken SWM Gear Shaft in Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens

    This is the gear between the SWM itself and the Focus Gear that engages the drive gear on the Focus Ring. The shaft is part of the Fixed Barrel and thus made of the same plastic as the structure. While it isn't likely to break during normal use, it can get stressed when going inside to repair something else, particularly during the removal or replacement of the Fixed Shell.

    If it fractured at its base, the original shaft can be reused but if it fractured in the middle, a substitute shaft will be required which can be made of metal. Note that the original shaft is NOT a constant diameter but is thinner at the top. It is not known whether this is essential if a replacement shaft is used. It probably allows for a larger tolerance in the positioning of the metal fork of the Autofocus A/M switch.

    Either way, a hole will need to be drilled perfectly centered and square in the Fixed Barrel so that a replacement shaft can be installed. The diameter at the base is approximately 0.045 inches but this should be confirmed. Ideally it will be a press-fit without requiring adhesive.

    1. Refer to the instructions in the section: Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR II Zoom Lens Disassembly and follow them to the step where the Fixed Shell is removed along with the SWM and Focus Gears.

    2. Arrange for any protruding cables to be well away from the area of the SWM Gear shaft.

    3. Using a drill press and 0.040" bit, very carefully drill a hole to a depth of around 3/32".

    4. Test to see if the broken or replacement shaft will fit the hole. If close, it can be widened with the tip of a needle file or a slightly larger drill bit. But avoid going oversize.

    5. Once the replacement shaft just barely fits in the hole, it can be gently pressed into place. Using a bit of non-softening plastic adhesive may be worthwhile.

    6. Check the fit and then following the reassembly instructions.

    Nikon AF-P DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens

    I have not found a repair manual or even an exploded diagram for this lens. If anyone has one, please contact me via the Sci.Electronics.Repair FAQ Email Links Page.

    Nikon AF-P DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Description

    The following applies directly to the Nikon AF-P DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens and probably mostly to the non-VR version as well.

    The AF-P lens is optically very similar to the AF-S versions, above, but with one additional lens element. However, it uses the Nikon so-called "Pulse" technology (thus the "P" in AF-P) for autofocus instead of the "Silent Wave Motor" (SWM, or S in AF-S). Pulse autofocus is based on a stepper motor and does indeed appear to be quieter than silent. ;-) While SWM uses a piezo motor driven at an ultrasonic frequency (above human hearing) which in itself should be very quiet, the motor's rotating surface plate in contact with the actual PZT element, associated gear train, and other rotating parts makes detectable noise.

    So AF-P lenses return to motor technology with magnets and coils. ;-) As noted above, the "P" is supposed to stand for "Pulse", which kind of applies. They are claimed to be even quieter than AF-S lenses and that is probably true. The manufacturing cost is also much lower. ;-) And there have been comments on various forums about AF-S autofocus reliability, which is quite credible given their complexity and opportunities for contamination to get to the motor. So perhaps a little of both. Replacing the piezo motor with a stepper motor also allows the AF-P lens to be more compact since the motor itself is less bulky and the high voltage drive components and gear train are eliminated.

    However, AF-P lenses are not compatible with the D5100 or D3200 (or earlier) cameras that are happy with AF-S lenses. Others like the D5200 may need a firmware upgrade (but that is a free download). And since there is no VR switch on the AF-P lens, VR is always enabled on these cameras since there is no electrical contact in the camera body to control it. (The AF-P version has 8 contacts compared to 7 on the AF-S.) But this incompatibility is almost certainly due to a business decision for planned obsolescence. There would not appear to be any reason why an AF-P lens could not have been designed to look like an AF-S lens as far the the autofocus commands are concerned. Or at worst, with a way of selecting the mode via a switch

    The AF-P lens is also significantly narrower than the AF-S VR lens and very slightly narrower than the AF-S VR II lens which could be in part due to the more compact drive setup. The piezo motor has a relatively large diameter (almost 1/2 inch) and the gear train also takes up space. For smaller lenses like these, the only option is to increase its overall diameter. The stepper motor with its direct worm drive can greatly reduce the required space.

    The AF-P lens destined for analysis is definitely well worn. The lock button doesn't work properly and in addition, one of the three tabs on the bayonet mount is broken off. Nonetheless, it still seemed to work well enough on a camera. But from the start, its days were numbered. ;-)

    After starting the dissection, I had other suggestions for the "P" in AF-P: "Pathetic" or perhaps "Plastic". Nearly everything structural is made of plastic except the screws, some specer rings/shims, and a few tiny brackets. The sleeve/barrel that "programs" the motion of the lens groups based on the zoom setting is a polished anodized aluminum cylinder with precision milled slots in the AF-S VR lens (and most likely the ED lenses that came before it). But it is made of plastic in the AF-P lens, though this change actually occurred with the AF-S VR II lens.

    However, having said that, the AF-P lens is much simpler and may be more reliable than its AF-S cousin. Autofocus has only two moving parts - a stepper motor with worm gear shaft which moves an internal lens group over a total distance of around 7 mm using low voltage drive. Compare that to reduction gears in the AF-S lenses along with the possibly tempermental ultrasonic piezo motor. The manual focus ring generates signals to the microbrain that then controls the same motor - it is not directly coupled to it: "Focus by Wire". Vibration Reduction (VR) is simplified as well with no Hall-effect sensors or lock mechanism. As a result, the electronics are also much less complex. In fact, as will be seen below, the electronics is perhaps an order of magnitude simpler in terms of the number parts compared to the AF-S version. This may be largely due to the lack of need for the high voltage piezo drive since the large ferrite transformers and drive components are eliminated. But may also be due in part to the higher level of integration available at the time of its design. And there are no critical surfaces to get contaminated as with the ultrasonic piezo motor. So I officiatlly retract "Pathetic" because the AF-P lens should be functionally at least as capable as the AF-S version, and more reliable without the SWM, high voltage drive, and gear train.

    But it almost appears as though this particular lens must be assembled from the inside-out. :( ;-) For example, in order to get to access any internal parts, the curved strip with contacts that make connections to the camera body must be disassembled down to its individual contacts, which then pop out all over the place. It isn't self contained with the flex-cable as in the AF-S. So if the plastic bayonet mount gets damaged (as would seem to be quite common even though this is a small light-weight lens), replacing it requires some serious manual dexterity. Nikon must have saved 3 cents. ;-)

    Taking it to bits non-destructively isn't that bad, though putting it back together without detailed instructions would be like solving a 10-level Rubik's Cube blindfolded. ;-) But that may be resolved soon.

    One mystery is solved though with respect to the silent propulsion system for autofocus. As expected and noted above, there is a very small stepper motor (~3/8" diameter) whose shaft has an integral worm gear and no other gears. That rests in a Nylon U-shaped bushing enabling the entire focus assembly with the 3rd lens group to be moved back and forth by around 7 mm with an opto-interrupter as a limit sensor at one end. The focus ring works in parallel with the manual focus electronically: There is an incremental encoder consisting of spokes on the perimeter of the focus ring with a pair of nearly microscopic opto-interrupters in quadrature to sense their movement. So, the stepper motor can be driven either by the autofocus electronics or focus ring essentially at the same time. It's "Focus by Wire". ;-) But manual focus will not work if power is off, which is only of academic interest unless the lens is used in an incompatible camera or for another application. This is fundametally unlike the AF-S version of this lens where the focus ring actually moves a lens group on a helical track and the A/M focus switch selects (1) whether it is coupled to the gear train and (2) lets the microbrain know.

    Without a gear train, this should be quieter than the AF-S. The stepper motor itself may make a detectable sound but sliding noise will reduced and there is no gear train to whine. But as a practical matter, the noise level of neither of these lenses is objectionable and only of relevance for some very specific applications where a "Do Not Disturb" sign is present. ;-)

    Nikon AF-P DX Nikkor 18-55mm f/3.5-5.6G VR Optics

    The AF-P has 6 lens groups (unlike the AF-S that has only 4), though some may be single lens elements.

    The position of the 1st and 2nd-6th (in the same relative position) lens groups move independently depending on zoom setting. The position of the 3rd changes relative to the others depending on focus setting controlled by the stepper motor.

    Most of the photos referenced below are also available as a Web Album (though possibly at slightly lower resolution) at Nikon AF-P DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Parts Web Album.

    Here is a summary of the Nikkor 18-55mm AF-P DX f/3.5-5.6G VR lenses I've acquired so far:

    1. ID #1 (SN: 24105203): The lens that came with my D5600.

    2. ID #2 (SN: None): The well worn lens used for the original disassembly but without enough attention to detail to call it a dissection. This only had a non-working lock button and broken bayonet mount. It did take pictures. I don't know if the SN fell off or was missing from the start. I should not have taken it to bits but waited for certifiably dead AF-P lens with good bayonet mount to transplant. Oh well.....

    3. ID #3 (SN: 22091057): Lock doesn't work but otherwise functional.

    4. ID #4 (SN: 21672615): Fully funtional placed in original box from one of the other AF-P lenses.

    5. ID #5 (SN: 24816754): Lock doesn't work but otherwise functional.

    6. ID #6 (SN: 20566872): Lock doesn't work but otherwise functional.

    7. ID #7 (SN: 23321760): Fully functional.

    Finding a certifiably broken (defines as non-functional) AF-P lens has been a challenge. Sometimes it's a case of the seller testing using an incompatible camera or not realizing the lens won't be recognized if locked. I usually attempt to inform sellers of these possibilities. Really. I haven't gone so far as to ask for a refund because the lens works though. ;-) As can be seen, the lock doesn't lock on most of these. Can you say "poor design"? ;-) There is a plastic ridge on the inside of the zoom barrel and gets damaged if attempting to rotate it without pressing the lock button. Or something. So that doesn't qualify as "broken". :)

    Nikon AF-P DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Disassembly

    Not all of the following is needed depending on whether this is for repair or curiosity. Do NOT do this if the future of the Universe depends on getting the thing back together in a functioning condition. ;-)

    That's basically it. There are now a pile of parts where there used to be an AF-P lens. ;-)

    Nikon AF-P DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Resassembly

    Reassemble in reverse order, left as an exercise for the student or masochist. ;-) More to come.

    I have been able to reassemble it into a mechanically correct configuration, though that was a challenge. While it's reasonably straightforward to get the major pieces screwed into their proper place, fitting them into the appropriate combination of grooves and slots in the cylinders that control how far each one moves as a function of zoom is a challenge. There are probably match-marks in conjunction with jigs that to the trained (Nikon) eye would make this intuitively obvious. The parts now move in what appears to be the correct way based on zoom, but that was through random chance. There are 3 separate assemblies that move based on zoom that need to go into their respective grooves and slots, and also need to be correctly oriented with respect to the quasi-3-fold symmetry of the lens, so among other things, the zoom distance labels, and mark and lock line up correctly. This will become more straightforward with experience, but certainly is a challenge the first time.

    And having been successful with the AF-S VF II, I am optimistic that this one will yield to enough determination.

    The more I look at these, the more they appear to be marvels of engineering down to the casting/molding of the numerous circuitous groves, slots, holes, posts, blocks, and other structures in plastic. It's probably just Zoom Lens Design 101 but still impressive to the uninitiated. ;-) Unfortunately, sometimes they aren't strong enough as will be seen with the 18-70mm lens, below. :(

    Nikon AF-P DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Dissection

    Similar to the one for the AF-S VR II lens, Coming soon, maybe. But for now, there is a Web Album at Nikon AF-P DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens Dissection Web Album with some stock photos and optical architecture and how the lens groups move with zoom.

    Nikon AF-S DX Nikkor 18-70mm f/3.5-4.5G ED IF Zoom Lens

    There is a repair manual on-line. Search for "Nikon AF-S DX Nikkor 18-70mm f/3.5-4.5 Zoom Lens Repair Manual" (without the quotes). It's the first hit using Google.

    Nikon AF-S DX Nikkor 18-70mm f/3.5-4.5G ED IF Zoom Lens Description and Dissection

    This lens is interesting because autofocus uses a full diameter ring ultrasonic motor with no gears, which is why I bought it for dissection. These are called "SWM Ring Motors" or simply "Ring SWM". Theoretically, they should be quieter, more reliable, and faster. But in reality, they may not be unequivocally any of these. The working sample I have is definitely not silent. And they are probably more expensive to manufacture even though there are fewer parts.

    Autofocus on this lens is quick, but not necessarily quieter than on the AF-S lenses using the small motor and gears. The motor and lens has sliding surfaces which still make some sound.

    But the sacrificial victim makes abnormally loud grinding noises and fails to be able to focus correctly - either manual or auto. :( ;-)

    The cause became obvious as a huge part - the entire 2nd lens group - was loose inside the lens not attached to anything just bouncing around. ;-( Figuring that the 1st lens group would detach like the others - by unscrewing it after removing the label, that was attempted first. But either it has left hand threads or it is really tight and I don't have the needed spanner wrench, so it remains securely attached. No matter. ;-)

    Plan B was to go in from the back, where the action is in any event. This turns out to be quite simple and even reversible. Removing several screws around the side of the bayonet mount and the back allows both to be removed without damaging anything. The electronics PCB is then exposed and its cables can be unplugged easily along with the A/M switch revealing the full diameter autofocus ring motor. The contacts remain safely inside their housing.

    Nikon AF-S DX Nikkor 18-70mm f/3.5-4.5G ED IF Zoom Lens Photos and Description

    Most of the photos referenced below are also available as a Web Album (though possibly at slightly lower resolution) at Nikon AF-S DX Nikkor 18-70mm f/3.5-4.5G ED IF Zoom Lens Parts Web Album.

    Being simpler than the VR lenses, there are fewer photos for this one, but there is always the on-line repair manual to refer to:

    This lens appears to be more repair-friendly than the ones above especially if there is no need to go inside the assembly with the 7th-13th lens groups. There should be no need to unsolder any wires and the flex cables detach easily. As noted above, just keep track of everything with photos, notes, and added match marks.

    However, note that there is a magnetic strip and magnetic pickup that provides a signal in place of the tachometer in some lenses that have the small SWM with gear train. Not only is it delicate and damaged easily, but ferrous tools can cause the magnetic pattern to become corrupted, which needless to say, would not be good. Even accidentally touching the strip with a slightly magnetic screw drive could potentially erase it.

    And if you're curious as to how the focus is controllable mechanically both via the Focus Ring and Piezo Ring Motor (PRM) at the same time, it's similar in concept to a differential gear box but with no gears. Focus is actually controlled by a ring with a metal fork that engages the plastic tab on the middel lens cluster. That is mounted on ball bearings as shown in the photo above. On the front-side is a plastic ring that is in contact with the ball bearings that engages with the rubber/plastic manual Focus Ring. On the back side is the rotor of the PRM which is in contact with the opposite sides of the ball bearings. The friction of the focus fork ring is quite low (or should be) so when the ball bearings are rotated by either the Focus Ring or Piezo motor rotor, it moves at 1/2 the rate of either but does not (or at least should not) affect the other ring. However, where the lubrication had gummed up or there is damage from abuse as in the AF-S DX 18-200mm f/1:3.5-5.6G VR II lens (below), this may fail to work properly.

    There are no immediate plans for a detailed dissection but for now see the Nikon AF-S DX Nikkor 18-70mm f/3.5-4.5G ED IF Zoom Lens Dissection Web Album. There is no dissection yet but it shows some stock photos and the optical architecture and how the lens groups move with zoom.

    Attempted Rebuild of Nikon AF-S DX Nikkor 18-70mm f/3.5-4.5G ED IF Zoom Lens

    For lack of something better to do I purchased a partially disassembled 18-70mm lens to try to make one good lens out of the two. I was only $17.50 delivered. This one has an intact focus group but no PCB or bayonet mount and related parts. I opted complete it using parts from the lens with the broken focus lens group since only the parts in the back were missing. The repair manual is useful for this. And aside from some partially stripped holes melted A/M switch ;( it went together without incident, the camera recognizes the lens and even reads the zoom setting correctly (confirmed via the EXIF info). The autofocus PRM works but focus lock is only achieved if it is already very close to the optimal focus. Otherwise it womps back and forth from end-to-end of the focus range. So it could be that the focus tachometer is faulty or disconnected. It works fine with manual focus. With the mangled A/M focus switch, it cannot be set to manual focus, but autofocus can be disabled on the camera.

    While in principle, it would probably have been better to simply swap the focus lens group into the original lens, other parts may have been damaged in the initial discombobulation.

    And that's how it will remain!

    Nikon AF-S DX Nikkor 18-200mm f/3.5-4.5G VR II Zoom Lens

    I have not found a repair manual or even an exploded diagram for this lens, though it is probably very similar to the VR (not II) version for which there is a manual. If anyone has one for this lens, please contact me via the Sci.Electronics.Repair FAQ Email Links Page.

    I do have one in mint condition and another that is cosmetically nearly as good but does not focus reliably, even in manual mode. But there are no current plans for a detailed dissection of either, or even to investigate this lens in greater detail unless someone would like to donate a sacrificial specimen for analysis. The asking prices on eBay are way above may curiosity quotient for a lens to take apart and likely never put back together so it functions. ;-) Appropriate chants and incantations will be issued to the gods of dead camera lenses upon request but it will not likely survive the experience. :( ;-)

    However, eventually the one with the unreliable focus may end up being used for this purpose.

    But see the Nikon AF-S DX Nikkor 18-200mm f/3.5-5.6G VR II Zoom Lens Dissection Web Album. There is no dissection yet but it shows some stock photos and the optical architecture and how the lens groups move with zoom.

    These photos were taken using one of my trusty D70s with the AF-S 18-55mm ED lens that had a damaged Filter Ring. See: Repairing Broken Focus Tabs on Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G ED Zoom Lens.

    Nikon AF-S DX Nikkor 18-300mm f/3.5-6.3G ED VR Zoom Lens

    This is believed to have the highest zoom ratio - over 16:1 - of any Nikon DX lens. There are at least 2 versions of the 18-300mm VR lens. This is the newer and lighter one but it has lost a fraction of a stop at the high end - 6.3 versus 5.6 which is considered mostly irrelevant with modern DSLRs.

    I have not found a repair manual or even an exploded diagram for this lens, though it appears to be generally similar to the 18-200mm VR and 28-300mm VR versions for which there are manuals. If anyone has one for this lens, please contact me via the Sci.Electronics.Repair FAQ Email Links Page.

    I purchased a certifiably broken sample and it was used for my photos below. But not inside yet. The main issue is that VR does not do anything. That could be as simple as a bad switch or wire that came off. This is a well used lens but focus (A and M) works and while zoom is a bit hard to move at times, nothing appears really damaged, though there is a serious nick in the lens hood mount ring (visible in some of the photos) so it has experienced some trauma.

    See the Nikon AF-S DX Nikkor 18-300mm f/3.5-6.3G VR Zoom Lens Dissection Web Album.

    This lens does take photos as long as one is careful to avoid camera shake, so reducing it to parts may not happen for a while. But the back was opened to check for obvious problems. The flex cables were all secure and the VR switch was tested so an easy fix is unlikely. However, if removing the bayonet and related parts, make sure to record the precise location of the brass shims - which I of course neglected to do initially. This lens has 2 and they are not identical so the orientation and also which one is on top may matter, though it's not clear why. And when reinstalling the aperture tang, take care that it goes into the correct location in the aperture actuator. Unlike many other lenses, it's a rectangular hole on this one, not just cup or U-shaped lever. It can slip in outside the hole and while it may appear to work when first installed, when the Inner Ring is put in place, it will jam. Other than that, reassembly is quite straightforward. There are only 4 types of screws and where they go should be intuitively obvious. ;-) But some are quite small so losing them is too easy and would be bad. ;-( And don't overtighten them!

    As they say: "If it ain't broke, don't fix it.". After going inside, two things changed: First, the image through the viewfinder "jerks" initially when the camera is turned on and the shutter is pressed, but only when VR is on. However, VR doesn't do anything else. This indicates that VR is being powered but is jamming to one side. I don't think VR did anything when first testing the lens. So perhaps that's an improvement. ;-) Second, autofocus stopped working reliably. I could have sworn it wasn't like that initially. Sometimes it would lock but usually it would either get stuck at one end of its range, or continue hunting back and forth around the optimal focus unless very close, in which case it might lock. So the back parts were removed again and it was discovered that one of the brushes in the Focus Encoder wasn't contacting the encoder strip. I have no idea how that could have occurred during the excursion inside as it's safely recessed. But once the brush was "adjusted", autofocus is back in shape. The microbrain had no idea where focus was at any give time so it didn't know what to do. Poor thing. ;-)

    I also reseated all the internal flex cables at the same time as dealing with the focus issue but that didn't make any positive difference to VR.

    However, now the lens produces 4 "clunks" about 1/2 second apart when the camera is powered up and sometimes when it's powered down regardless of whether VR is on, independent of zoom and focus settings, but only with autofocus enabled. They sound like they are coming from the vicinity of the VR assembly but don't appear do anything to the image in the viewfinder. The count of 4 is digitally precise and the behavior is totally repeatable. Go figure.

    Having said all that, the lens takes great photos and therefore I have no plans to go inside again.

    But stay tuned.

    Miscellaneous

    Nikon DSLR Doesn't Recognize Memory Card

    This may be specific to the D5x00 DSLRs when attempting to use a brand new SanDisk Ultra 32GB SDHC. The message is "This memory card Cannot be Used. Card is Damaged. Insert another card." Then nothing responds, even the configuration menus, so it cannot be formatted in-camera. And formatting it on a PC using either NTFS or FAT32 makes no difference. A Web search will return all sorts of suggestions. But the simplest is to format the card in a Canon camera. Really. ;-) The specific case here is a Nikon D5200 and Canon SX710 HS. This was not a fluke with a single card but happened on more than one occasion.

    Nikon Electronic Flash Issues

    WARNING: All electronic flashes using xenon lamps have an energy storage capacitor that can hold a high voltage charge for hours to days even with the camera off, the flash disabled, or the battery removed. The 330 V capacitor in a D70 still had more than 250 V on it after at least a day with no battery. Touching the wrong contacts can result in a shocking experience (though probably not a lethal one). But it can kill the camera if it ends up discharging through the electronics. This only matters if disassembling the camera for repair or curiosity and then mostly in areas relating directly to the flash or capacitor. It is not something the user of the camera needs to be concerned with unless the case is damaged, particularly in the areas of the flash or capacitor (whose location depends on the specific camera model). And with the flash cover removed (as might be required to repair one that doesn't pop up), both ends of the flashlamp are exposed. The risk is not necessarily between them as there is an IGBT or a similar electronic switch in series with one side to implement the energy conserving flash control, but between the live contact and other parts of the camera. And that can not only be shocking but kill the camera as well. Discharge the capacitor at the capacitor terminals using a power resistor - 10-15K recommended while monitoring with a DMM to below 1 V or so. Then short across them with clip leads and leave them there for awhile. (Capacitors can recover some charge on their own.) DO NOT just put a screwdriver blade across the terminals as there could be a rather dramatic flash-bang with collateral damage to the shorting tool and terminals. See the document: Electronic Flash Units and Strobe Lights for more details including safety precautions.

    Nikon AF Lens Zoom and Focus Roughness

    If you're used to the silky smooth operation of a classic Nikon lens like those for Nikon film SLRs, it will be a bitter disappointment to use a modern Nikon DSLR zoom lens. Lenses like the 50 mm f/1.4 "standard" lens or 43-86 f/3.5 zoom lens were works of art in comparison. They were mostly made of machined aluminum and well lubricated. Many samples 40+ years old still perform like new.

    Modern lenses are much more sophisticated and no one would want to go back to the fully manual older ones, but silky-smooth operation is not one of their features. And it's easy to see why. Most of the moving parts are made of plastic and a zoom lens has many of them. For example, see Major Moving Parts of Nikon AF-S DX Nikkor 18-55mm f/3.5-5.6G VR Zoom Lens. These all move when changing zoom or focus. The three cylinders at the top of the photo reside nested and rotate or slide with respect to each-other with a large surface area in direct contact. The center one is made of anodized aluminum with precisely milled slots that determine the required movement of multiple lens groups with respect to each-other when zoom is adjusted; the other cylinders are formed or molded plastic. The straight slots in the upper-left (outer) cylinder guide those moving parts that must not rotate. Pegs or rollers (without ball bearings) restrict their movement to the AND of the slots in the upper left and the other cylinders, but also add friction. Some parts reverse direction as the Zoom Barrel is turned, adding additional friction/resistance at that point. It's all rather intricate and I bet Nikon has a really nifty CAD package for zoom lens mechanical design. ;-)

    As an example of a common much larger lens, see the diagrams in Nikon AF-S DX Nikkor 18-200mm f/3.5-5.6G VR Zoom Lens showing Lens Group Positions at 18 and 200 mm. Lens Group 3 and the VR assembly move together, but those and all the others move relative to one-another and relative to the lens structure attached to the Nikon F mount.

    Even on a brand new lens, there is detectable roughness and varying resistance over some parts of the zoom range. Over time, the lens will be exposed to dust, moisture, and contamination either from normal use or from being tossed in a storage bag, it gets worse as there are no real seals. And plastic is subject to wear. The good news is that for the most part, none of this makes any real difference in picture taking performance. That is, until the thing seizes up completely or falls apart. :( ;-)

    But if the lens is dropped or whacked, parts like those pegs can get broken off or may dig into the tracks with varying degrees of damage. In minor cases, the roughness will just become worse but with enough trauma, major functions will stop working. When considering the purchase of a used lens, carefully check autofocus, manual focus, and vibration reduction, as well as for correct operation of the aperture at all zoom settings. Don't accept a lens where manual focus doesn't work reliably even with a discount (as I once did) because the seller said no one ever uses it. While that may be partially true, unreliable manual focus can be a symptom of more major problems. One thing that is often broken on used lenses though is the Lock button if there is one, used to secure the lens in a compact state for storage. The internal lip that the button engages is made of plastic and users often attempt to twist the Zoom Barrel without realizing it's locked, so that lip gets damaged and the button non longer works properly. That alone is probably not sufficient reason for rejecting a lens - but perhaps it may be leverage to negotiate a discount! While Lock may not work or work well, the end-stops for the Zoom Barrel should not be affected. But this should be confirmed as bad things may happen on some lenses if the Zoom Barrel is rotated beyond the normal range.

    Mechanical versus Electronic Shutter Complexity

    For all except camera geek types, this is probably just in the "that's interesting department". ;-) Mechanically-controlled shutters - both leaf and focal plane type - are designed along the lines of precision time-pieces with springs, gears, cogs, escapements, and levers that open and close the leaves or blinds. But whereas clocks are supposed to run at a fixed rate, shutters typically have 10 or more speeds. Electronically-controlled shutters use a pair of solenoids to determine the timing based on signals from a microcontroller. As an example, see: Comparison of Mechanical and Electronics Focal Plane Shutter Complexity. The Copal Square S shutter on the top is from a Nikon Nikkormat FTN 35 mm film SLR; the one on the bottom is from an older Nikon D80 DSLR. (The photos have been scaled so that they are approximately the same size independent of the FX and DX formats.) To fine tune the mechanical shutter requires the adjustment of the torque provided by some springs, the position of specific parts, and even the selection of slightly different parts based on actual timing measurements. And even then, the actual shutter speeds may only be accurate or repeatable to within ±10% on a good day. For the electronic shutter, it is just firmware code which could be optimized automatically after assembly. ;-) Shutters in other DLSRs where control of the sensor itself is NOT used to determine exposure at any speed would be similar. For those cameras where the sensor is used as the high speed shutter like the D70, they would be even simpler. In principle, there should be no need for any mechanical shutter in a DSLR but for practical reasons, this is apparently rarely the case. Point-and-shoot cameras generally do NOT have a mechanical shutter of any kind.

    Copal Square S Focal Plane Shutter

    The original Nikon F used a horizontally-moving focal plane shutter with fabric curtains. The fastest flash sync was 1/60th of a second. The Nikkormat FT/N use a vertically-moving Copal Square S focal plane shutter with metal "Venetian Blind" panels with 3 slats each. It can flash sync at down to 125th of a second. The Copal Square S shutter is an example of the state-of-the art in mechanical shutter design. It is described as a workhorse which really doesn't break, though as with any mechanical system, may require cleaning and lubrication after a half century or so. However, it is common to find these dating from the 1970s or earlier in perfect operating condition. At first glance, the mechanism might appear to be too complex to have ever been designed by humans. Think of a mechanical pocket watch with 11 speeds. But it evolved from or in parallel with leaf shutters that have similar timing requirements.

    See the Web Album at: Copal Square S Focal Plane Shutter Mechanism. (The Web Album photos are scaled to fit within 1024x768 pixels but the full size originals have the name under the thumbnail with a ".jpg" added.) The first 4 photos are of a beat up Nikkormat FTN in various stages of disassembly starting with most of the pieces of the lens mount in place to revealing the Copal Square S shutter in situ. These are followed by closeups of another similar shutter. The primary difference between them is the use of a less expensive Nylon gear for the speed select compared to the highly polished brass one, and some slotted head screws in place of Philips head screws. Since there is no real stress on that gear, cheaper is just fine, thank you. ;-) My black dot on the white gear lines up with the post for the 1 second setting. In the interest of full disclosure, I have swapped the gear and screws to make the separate shutter mechanism more photogenic. And in the interest of expediency, the screws that secure the body parts have been left off. ;-)

    Two manuals relating to Copal Square S Shutter repair are known to be available on the Web and hard copies may be purchased on eBay and elsewhere. Both Copal Square S Shutter Repair Manual and Copal Square S Shutter Repair Guide are interesting reads, but they may not enable you to be able to do much in the way of repair. The first one does have a 75 (!!) step procedure with diagrams for assembling a shutter. ;-) Aside from the intricate nature of these mechanisms, special jigs and instruments are required for some of the procedures. However, cleaning and lubrication of specific parts may be possible. This will involve the use of solvents like alcohol or naptha along with an ultrasonic cleaner if available, followed by lubricating specific bearing points and surfaces ONLY with the tiniest speck of special oil or grease as appropriate. A shotgun approach of simply sprayng it with degreaser and adding oil anywhere that looks appropriate will likely result in a nice paperweight. DO NOT even think about allowing WD40 or anything similar near a precision mechanical device like this! ;( ;-) A Web search will turn up suitable procedures but take them all with a grain of sand.

    Control of the shutter bears similarity to that of mechanical leaf shutters, but it needs to determine the timing of the pair of blinds rather than opening and closing a set of leaves. For the Copal Square S There are three (3) regimes of timing:

    And as a matter of interest, operation of the shutter in a fully mechanical SLR and specifically the Nikkormat is as follows:

    1. The film advance lever cocks the shutter via a rack gear at the bottom of the camera, cocks the mirror mechanism via a lever linked to the rack gear, and advances the shot counter.

    2. Pressing the shutter button triggers the mirror to flip up.

    3. When the mirror reaches the fully up position, it triggers the actual shutter to open.

    4. Once the shutter has closed, the mirror returns to the down position.

    For the "B" setting, everything is the same except that a tab on the shutter linkage prevents the shutter from closing until the button is released. The actual shutter speed is probably forced to 1/1000th second so closing would not be delayed no matter how quickly the button is released. The Nikkormat doesn't have a "T" setting, but for that operation would be similar but there would be a simple escapement that would require the button to be pressed a second time to close the shutter.

    Optical Materials used in Nikon Lenses

    Until I started to dig deeper into the construction of these lenses, I had always assumed they used individually ground and polished glass optical elements. Sure, inexpensive pocket cameras have always used plastic optics, but Nikon-branded DSLR lenses? Really? ;-)

    It turns out that a variety of types of glass and plastic may be used and the optical elements may be either ground and polished or molded. Sometimes the lens specifications will include some information on the material thought probably NOT the fabrication method if the Marketing Department thinks it will help sales. For example, Extremely low Dispersion Glass (ED Glass) and aspheric are pointed out in the info for lenses like the AF-S DX Nikkor 18-55mm or 18-200mm. They probably won't state anything if plastic. ;-) If not specified, the material can be any either common optical glass (BK7, crown, flint, etc.) or plastic. Aspheric elements are probably molded since individually grinding and polishing them would be cost prohibitive.

    There is no easy way to determine the material and fabrication method non-destructively (or at least without some damage) on an intact lens as they appear identical. But even if the lens is disassembled into the individual lens groups it's a challenge. Glass is several times more dense than plastic so the weight of a lens group can be a tip-off, especially for the larger ones. Ground and polished lenses will generally have frosted edges while molded ones will have smooth lips and perhaps even tabs. But the overall appearance of the individual lens elements is essentially identical in terms of surface finish and AR-coating.

    Diagnosing Nikkor AF-S Autofocus Problems

    Nikkor AF-S lenses have a reputation for reliability problems. However, this may be undeserved at least in my experience. I've acquired some AF-S lenses in fairly dreadful cosmetic condition that worked just fine. And where there were focus problems, they have not been due to the SWM or related parts. However, these are more complex than the later AF-P lenses, both mechanically and electronically. The symptoms may be a total failure to focus, movement of the focus more likely in or out, or erratic behavior.

    Some possible causes are:



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