Repair: Nikkor-Q 200mm f/4

Hello, dear readers. I am sorry for posting this late but I was having a problem with the blog so I was not able to post this earlier. For some reason, I cannot access my drafts and my site would not load at all. That was all fixed when I decided to restart my Macbook Pro. This whole thing scared me because I have spent a lot of time writing and documenting for this blog and if all were to go down the drain then it would mean the end of everything for me! Anyway, now that it is all in the past we can now proceed with our subject for today!


Our subject for today is the amazing Nikkor-Q 200mm f/4 lens. I chose to write about this lens because I just finished  repairing one and a certain reader named Mister Chan is going to repair his Nikkor-Q 200mm f/4 lens.


img_2868Here is my collection of Nikon’s 200 f/4 primes. All of them were bought as junks and were restored during my spare time. These comprise all of the major cosmetic variants for this lens line and we will have a guide for each of these one of these days.

From left to right (chronological) you have:

  1. Nikkor-Q 20cm f/4 bis – This looks similar to it’s successor but there are a few small differences between the 2 in terms of construction. The latter lens was made more to be more durable and short cuts in production are also made to manufacture this lens faster/cheaper without compromising quality.
  2. Nikkor-Q 20cm f/4 – The subject of this blog post. While nothing much has changed from the previous version, there are numerous improvements made in productions to cut corners and also to make the lens more durable. Note that it’s slightly slimmer than it’s predecessor so parts are NOT interchangeable in most cases.
  3. Nikkor-Q 200mm f/4 – This is the last version of the Nikkor-Q range. The minimum focusing distance has been lessened to 2m, the handling and construction was vastly improved, the optics were tweaked a bit to offer better sharpness and the C version is probably the sharpest in this range because it uses Nikon’s multilayered coating.
  4. Nikkor 200mm f/4K/Ai – This version/s represent a total departure from the older lens range because the optics are totally different. The lens is also smaller and lighter, for many people this change alone is a big deal when deciding which lens goes in the bag or stays in the dry box. The K (New-Nikkor) and Ai versions are near identical so I have bunched them together in one group. I also made a guide for this lens, click on this.
  5. Nikkor 200mm f/4 Ai-S – This is the last version in this long series. Optically, it is the same as the previous one above but the construction is totally different. The coatings are probably different on the later ones but I have no data for this. Handling is pretty much the same as the previous version and cost-cutting decisions are obvious in the construction, very typical of Ai-S lenses (scotch tape,anyone?).

I got this lens for about $3.50 in the junk box of Kitamura’s Akihabara shop. The state of the lens was pitiful as the glass elements were covered in fungal growth. The lens exterior on the other hand looks OK for a lens of this vintage. It is not mint but I will consider this to be in apretty good shape as you can see in the picture above.

Many people consider this lens to be one of the most important lenses in recent history because this lens was responsible for bringing the telephoto lens to the masses. It was priced reasonably when it was released and was also small enough to be a regular part of the photographer’s kit. The reasonably fast f/4 aperture also allowed this lens to shoot most sports as well as for portraiture or landscape. The Tokyo Olympics in the mid 60’s also popularized this lens because photographers can now shoot telephoto lenses with confidence on an SLR system as opposed to rangefinders where parallax can result in a different framing altogether.

After fixing this lens, I shot with it at the park. I apologize for the poor samples because I shot these on a cloudy day and I was hand-holding my setup with a shutter speed of about 1/200s. The lens performed admirably. Sharpness was great wide-open at f/4 and stopping it down to f/5.6 will give you even better results. Stopping it down to f/8 will not give you a better image (maybe just a bit), it is that good! The handling is also amazing, this is a lens that you will want to use just because you like the feel of it.

This lens comes in 2 different versions. The original version of this lens had a narrower focusing ring, a shiny chrome front barrel and a minimum focusing distance of 3m. This lens is the improved (2nd) version with the wider focusing ring, a black front barrel and a minimum focusing distance of 2ft. The second version also performs better with color film as the first version was calibrated with black and whit film in mind so it has a blue color cast on film. The second version also comes with Ai kits in the later production lenses.

Having mentioned a bit about the lens’ history as well as it’s optical performance, let us now begin dismantling the lens!

Before We Begin:

If this is the first attempt at opening a lens then I suggest that you read my previous posts regarding screws & driversgrease and other things. Also read regarding the tools that you will need in order to fix your Nikkors.

I highly suggest that you read these primers before you begin (for beginners):

Reading these primers should lessen the chance of ruining your lens if you are a beginner. Also before opening up any lens, always look for other people who have done so in Youtube and the internet. Information is scarce, vague and scattered (that is why I started this) but you can still find some information if you search carefully.

I highly recommend that you also read my working with helicoids post because this is very important and getting it wrong can ruin your day. If I can force you to read this, I would. It is that important!

For more advanced topics, you can read my fungus removal post as a start. This post has a lot of useful information here and there and it will be beneficial for you to read this.

About Me:

I am a photographer based in Tokyo who scours the junk section of the camera shops here on a regular basis. I started this hobby of fixing old lenses and cameras because I kept on getting scammed before when I purchase online. This turned out to be a blessing because I now buy junk lenses for a fraction of the price and then fix them to add to my growing now collection. This allowed me to buy gear that were otherwise off-limits to me if I were to get them in better condition.

I was a scale modeller before who built models for other collectors for a very longtime, got an education as a dental prosthodontist (but didn’t pursue dentistry) and growing up in a watch repair shop gave me the useful skills that would help me in this craft. Fixing my car also contributed some know-how.

Having mentioned the above, I will tell you now that I am not a professional repairman! So please take what I do with a grain of salt and I will never be held responsible for anything wrong that will happen to you and your project. I hope that the pros would guide and teach us but nobody is writing anything.

As my collection of repair notes grew, I get requests from people with similar interests and from professionals who just needed some notes just in case. Now, I am sharing my library with you for your entertainment and reference. I hope that you find my work useful.


This lens was engineered in the typical Nikkor way so just imagine that you are fixing a 50mm lens that was scaled 3x and you are all set. Just with every lens that you want to fix, it is advisable to remove the objective (optical block) first so that you will not damage this part accidentally as you go about dismantling your lens.

I also recommend that you read my best practices series if this is your first time to open up a lens for servicing to avoid making any mistakes.

Disassembly (Front Barrel):

We usually begin with the front barrel when it comes to Nikon’s prime lenses and this lens is no different. There is nothing noteworthy but you should expect that glue has been used here and there so you will want to borrow your wife’s acetone (nail polish remover).

IMG_2376Start by removing this tiny set screw in the focusing ring and be careful not to damage it.

IMG_2377With the tiny set screw gone, you can now safely turn the front cover of the focusing ring counter-clockwise to unscrew it. This part is usually held tight and is frequently glued so use solvents like acetone or MEK (Methyl Ethyl Ketone) to soften it up first before you start turning. Note the indentation on the threads, this is where the set screw is sunk into so to prevent the front cover from being removed accidentally.

IMG_2384To remove the front barrel of the lens housing you have to remove another set screw that can only be accessed by focusing the lens to it’s minimum focus distance. Be careful, mine was so old that the set screw broke into pieces as I was turning it with my screwdriver! I was careful but lenses of this vintage can be fragile at times.

IMG_2386You can now unscrew the front barrel off  and be careful not to drop the objective!

IMG_2387To remove the built-in hood, you must first rotate the hood until you see the tiny set screw that is securing the filter ring to the front barrel. This may take some time to find so just be patient with it when you could not find it the first few tries.

IMG_2388With the set screw gone, you can safely unscrew the filter ring. Depending on the lens, the filter ring may be secured by adhesives or may even be over-tightened at the factory so use a bit of caution when removing this.

IMG_2389Be very careful when pulling the built-in hood away from the front barrel because you do not want the spring and bead to fly across the room! Mine did because I did not know what to expect. There may be more parts than the ones shown but these are the only ones that I found on the floor so far. This spring and bead mechanism is responsible for the clicking action that holds the built-in hood in place.

IMG_2382On to the other end of the lens. Be careful when handling the lens, the front barrel is now gone so the objectives have the potential to free-fall into the floor by the virtue of it’s own weight alone! Check that fungus damage on the rear element, yuck!

Remove these 5 screws to remove the bayonet mount from the lens. This will ensure that you will not bend anything accidentally while pulling the objective away from the lens.

IMG_2385You can now remove the bayonet mount and the aperture ring should easily come off with it. Just be mindful not to damage the small spring.

IMG_2393The objective can now be removed without any resistance now that the bayonet mount is gone. Store the objective in a safe place because you do not want this to roll off the edge of your work table!

Disassembly(Focusing Mechanism):

IMG_2394Start by carefully removing these 3 screws that secures the focusing ring. These screws are also used for focusing alignment so take note if their position before you remove it. There is a likelihood that you will re-adjust your lens’ infinity focus later when you re-assemble your lens and this is just one of two ways for you to adjust it.

IMG_2395The focusing ring should come off once the 3 screws are gone. You will also need to focus your lens close to the minimum focusing distance to give you enough room to remove the focus ring because of the interlocking nature of focus ring’s mount so do not force it.

IMG_2396Now, re-focus the lens back to infinity and note the infinity position of the helicoids.

IMG_2397To access the helicoid key’s screws you have to remove these 3 screws that are securing the chrome sleeve to the main lens barrel.

IMG_2398With the screws gone, you can safely remove the chrome sleeve from the lens.

IMG_2403Rotate the barrel until the screws of the helicoid keys line up with the holes on the main barrel. Carefully unscrew the screws to remove the helicoid key.

IMG_2405With the helicoid key gone, you can now separate the outer helicoids. Be careful and note where they separate because this is also the same spot where they should be mated when you reassemble your lens.

IMG_2406The innermost helicoid is best separated by turning the inner helicoid until it exists from the bottom of the main helicoid. In order to do that, you have to remove these 2 screws so that the inner helicoid can pass through or else the helicoid stop (the one with the screws) will prevent it from doing so.

IMG_2407Remove the 2 screws to remove the helicoid stop. Be sure to mark where the inner helicoid and the main helicoid separate.

IMG_2408For a thorough cleaning, you would want to remove the this ring from the main helicoid. Just unscrew these 3 tiny set screw and apply acetone or any strong solvent to weaken the glue that Nikon used to remove it. It may take some time for the glue to soften because we are dealing with a glue that has set around 5 decades ago. Nikon also tends to use stronger glues on these parts so don’t force your way. Just give the solvent 30 minutes to an hour to work on the adhesive.

IMG_2412This is the main reason why I would like to clean this part despite the effort and potential need to re-align this part again during disassembly. Old lubricant tends to get deposited under the ring and around the threads and this is a potential problem for you when this decades old lubricant gets mixed with your fresh grease and starts a chemical reaction so that your fresh grease starts to gum up after a few months. I learned this from my old auto mechanic (the name’s Rudy) while he was repacking the old bearings in my car.

IMG_2409To remove the aperture claw assembly, you have to remove this post first. Be careful not to use excessive torque when removing this part and specially when re-installing this later because this part can easily snap in two when over tightened.

IMG_2410Finally, remove the 3 set screws that secure the locking ring of the aperture claw assembly. I personally believe that a simple copper tension ring is more than enough for this purpose and tension rings will last longer against the wear and tear of regular maintenance but this is what Nikon did so it might be fine.

IMG_2411.JPGAnd there you go, the aperture claw and it’s locking ring can now safely be removed.

Disassembly (Objective):

The objective for this lens is HUGE! The lens elements are heavy so be careful not to drop it on the floor!

IMG_2414First, separate the front elements and it’s case by unscrewing it from the objective’s main casing. You may need to apply solvent to soften up the glue that was used to secure this.

IMG_2413Next, use a lens opener to unscrew the ring that holds the front element. Be careful not to damage the glass!

IMG_2427The front elements assembly consists of 2 separate glass elements. Remove them both by using a lens sucker. Be careful when removing the front element because you do not want the 2nd element to drop to the floor! That tiny gasket you see in the picture on the 1st row lies between the 1st and 2nd elements.

IMG_2415To remove the middle element, use a compass to unscrew it from the main casing. The tips of the compass should fit into these two holes. You can also see the extent of the fungus in this picture. The rear element is even worse.

IMG_2419Carefully pull out the assembly with your fingers or use a lens sucker.

IMG_2420The retention ring took me a long time to unscrew because it was being secured by paint so acetone had no effect on it, instead I used lighter fluid to soften the paint up before I can safely unscrew this thing off.

IMG_2424You can use a lens sucker or simply drop the middle element into your palm. If it is stuck, do not force it. Use your finger to push it from the back and it should move a bit. The edges can easily chip or get scratched when you use excessive force so be careful.

I usually mark the edge with a soft pencil to indicate which way the element should face so that I will not accidentally put an element back in the wrong direction. The mark does not need to be big, a small 1mm arrow or triangle should be perfect for this.

Unscrew the other end of the objective and you can access the iris. Mine looks fine so I left it alone but the bottom of the cover had some fungal growth on it so I had to clean it.

IMG_2416.JPGTo clean the rear element, just unscrew the retention collar and carefully pull it out using a lens sucker. Mine needed some acetone because it was being held by an adhesive

IMG_2426Be careful with the retention collar, mine had felt paper glued to it but I forgot everything about it so I dunked it in my alcohol bath! As a consequence, I had to scrape away the old damaged felt.

Post Mortem:

This lens is pretty easy to take apart and reassemble but surprisingly, it took me about 3-4 nights to fix mine. The size of the parts might have contributed to it since I clean the parts as best as I can and that means more surface area for me to scrub and rub! Also related to the size of the parts, the grease needed to lubricate this is 2-3X more than what I would normally use on the usual Nikkor prime so I ran out of my regular S10 helicoid grease after I serviced this lens.

There are a few things that you will need to be careful of. One is the felt lining on some of the parts like the baffles and hood. To clean them, just use the sticky side of a scotch tape and use it to pick up any lint or fibres from the lint.

The helicoids are pretty easy to reassemble but you have to be careful with the innermost helicoid. Mating this helicoid to the main (middle) helicoid can be tricky if you try it the usual way (from the front end). It connects rather easily when you mate it from the other end of the main helicoid so separate the inner helicoid from the bottom instead of the top.

IMG_2425I cleaned the fungus off each element using ammonia and hydrogen peroxide. Check the crescent shaped fog on the lens where water is not forming beads or droplets, that is the place where the fungus damage was worst. It is invisible when dry and does not even affect the image quality of the lens but the fungus has etched the glass enough so that water will not form beads there because it is not super smooth anymore due to the micro etching.

IMG_2428Oh, so clean! The only way to tell this lens’ history is by using blacklight. You will never know a lens’ history when you found one in the used market specially if it was serviced by a competent technician. If somebody like me can manage to clean it to this state, a real professional should even do a better job.

IMG_2431When putting the lens together, you will need to re-adjust the infinity focus and this is the place where you should do it. Adjust your lens before you put the focusing ring back or else it is going to be frustrating because you will have to remove the focusing ring again just to get back to this part.

The screws used for this lens tend to be smaller than what I would expect. An example of it are the screws on the helicoid key. For a lens this scale, Nikon should use M1.7 screws for the helicoid key, instead they only used the small M1.4 screws. The case is also true for the focusing ring and the adjustment ring underneath it.


IMG_2429The lens is a masterpiece of optical engineering. Nikon made a lens with only 4 elements in it, resulting in pictures with saturated colours. The ergonomics of the lens is also good, the weight balances perfectly on most Nikon camera bodies but a built-in tripod mount is certainly going to be welcome since the whole setup is very front-heavy.

I have also converted this to be Ai compatible. Please do check my post regarding how I go about converting my pre-Ai lenses to Ai. There are many ways to go about doing it but this method is by far the cleanest way that I have tried.

IMG_2430Here it is beside it’s successor, the Nikkor 200mm f/4 Ai. As you can see in the picture, the new lens is a lot smaller. The optics have been changed as well by adding another element. The handling has also been improved considerably as a result of the lens being redesigned. For many, this is enough reason to dump the Nikkor-Q 200mm f/4 in favor of the new one, and that is also the reason why you are seeing a lot of Nikkor-Q 200mm f/4’s being sold in the market today for such a low price. It’s not that the older lens performs poorly but it’s successor was just an amazing lens that it outperformed it’s predecessor. You can use this to your advantage if you want to own a piece of photography history as well as own a great lens for the price of a premium steak (with potatoes on the side).

I hope that you guys enjoyed this blog post and I apologize for the late post. If you enjoyed this post then please feel free to share or pst this article anywhere you like. Thanks, Ric.

Help Support this Blog:

Maintaining this blog requires money to operate. If you think that this site has helped you or you want to show your support by helping with the upkeep of this site, you can simple make a small donation to my account ( Money is not my prime motivation for this blog and I believe that I have enough to run this but you can help me make this site (and the companion facebook page) grow.

Helping support this site will ensure that this will be kept going as long as I have the time and energy for this. I would appreciate it if you just leave out your name or details like your country and other information so that the donations will totally be anonymous it is at all possible. This is a labor of love and I intend to keep it that way for as long as I can. Ric.


29 Comments (+add yours?)

  1. Ron V.
    Mar 08, 2016 @ 20:18:41

    Once again, great work Rick.
    Thanks for the warning about the ball & spring detent arrangement!


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  3. Pablo
    May 31, 2016 @ 23:43:17

    Hi Rick! Great post! Would love to see the Nikon 200mm f/4 Ai disassembly though as I am facing it as my first project!
    Happy to see the joy this historic lenses have to give.


  4. Trackback: Nikkor 200mm f/4 K/Ai | Richard Haw's Classic Nikkor Maintenance Site
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  7. Gustafson
    Mar 05, 2017 @ 06:30:16

    Great guide! I have a 200 f/4 Q.C that it will come in extremely handy for. Any chance you have taken apart the 300 f/4.5 ED-IF AI-s, or the 24-120 AF-D ED-IF? Instructions would be greatly appreciated! Thanks!


    • richardhaw
      Mar 05, 2017 @ 10:37:09

      Thanks, Gustafson!
      I have the 300/4.5 pre-Ai one, unfortunately. Maybe I can find one on the Japanese net for you. Ric


      • Gustafson
        Mar 07, 2017 @ 10:45:23

        Thanks, Ric! That is very nice of you to offer and greatly appreciated.

        On a separate note, I’ve managed to strip the screws on the mount in some older Nikon hardware, such as the 300 f/4.5 ED-IF and a PK-13 tube. Do you have suggestions for avoiding such occurrences, and how to salvage the situation if it does occur? I’ve tried lightly spraying lubricants on the screws (WD40, lithium grease) and using the correct size JIS screwdrivers, but I still end up stripping screws at a frequency higher than I would like, and would like to eliminate the issue if possible. Thanks in advance!

    • richardhaw
      Mar 07, 2017 @ 13:06:20

      Hello, Gustafson! Have you read my screws blog post? You have to apply pressure to the screws. WD40 won’t do anything,too. If you can recall I kept on reminding people to use solvents on these screws or use a mini torch when all else fails. Ric.


      • Gustafson
        Mar 11, 2017 @ 11:52:59

        Ric, thanks for the pointers. I did go back and read your guides, and appreciated the suggestions on using long-shaft JIS screwdrivers, and acetone or heat if needed. Also, the specific suggestion of a dremel and the micro screw extractor was helpful. Can’t wait to try those out. As for info on the 300 f/4.5 ED-IF, thanks for pointing me to those sites. I didn’t know those resources existed, and you’ve given me two more places to look for my other lenses!

      • richardhaw
        Mar 12, 2017 @ 02:45:04

        Hello, Gustafson.
        I will probably make a video one of these days to prevent people from stripping their screws. No matter how hard I warn people, there are people who will always strip the screws. I also found out that there are 2 versions of the 300/4.5 non-Ai. Ric.

    • richardhaw
      Mar 07, 2017 @ 13:11:57

      Hello, Gustafson.

      Unfortunately, there is nothing much on the net about the ED version. I only found these 2. Ric.


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  11. John Strandberg
    Jul 12, 2018 @ 00:23:56

    Richard, I want to remove the bayonet ring from my Nikkor-Q 200 F4 so that I can lengthen the detent slot slightly. (so the lens will securely lock to the Nikon to Canon adapter I have.) I have removed the five screws but the ring will only lift out about 1/4-inch before something catches internally and prevents me from lifting the ring free. Any help you can provide would be greatly appreciated. Thanks, John


    • richardhaw
      Jul 16, 2018 @ 15:49:16

      Hello, there shouldn’t be any problem if you followed my procedures. Maybe it’s a screw at the aperture ring? Ric.


      • John Strandberg
        Jul 17, 2018 @ 00:36:12

        No luck Ric. The aperture ring can be lifted up about 1/4th inch also but the bayonet ring still feels like some part is catching internally below the aperture ring. I have not removed the front barrel assembly so I am wondering if I can remove the bayonet ring without removing the barrel assembly?

      • richardhaw
        Jul 17, 2018 @ 00:39:48

        Try extending it and try again.

  12. John Strandberg
    Jul 17, 2018 @ 00:47:35

    Thanks very much, that did it!


  13. Reed
    Oct 26, 2018 @ 22:20:53

    You really helped me salvage a lens! Thank you so much. Mine did not have the glue problems yours did, and the cleanup went very smoothly!


  14. Trackback: Report: Nikkor Prototypes (Part 5) | Richard Haw's Classic Nikon Repair and Review
  15. Dex
    Feb 06, 2019 @ 16:45:18

    Richard, Very good article! I am taking delivery of the 200mm f4 this week and will be converting to AI. Are there any issues you see with removable of the mount and re-assembly once the modification is complete?


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