Repair: Nikkor 35mm f/2.8 Ai

Hello, everybody! I hope that all is good with you this weekend. I am currently busy with my film cameras so I am finding a great workflow to digitise my negatives. I have not shot film for years and I will admit that I did not learn a lot back then because shooting film is not cheap then as it is now. Rediscovering film has been fun and nostalgic for me. If you have a great film digitising workflow then please do not hesitate to share it with me!

I was suppose to write the second part of the Micro-Nikkor 5.5cm f/3.5 Preset article that I posted last time but there was a need for me write this article to help somebody up so that will have to wait for a few more weeks.


IMG_0587.JPGIn this post, we are going to talk about the Nikkor 35mm f/2.8 Ai lens. This lens is one of my favourite lenses for street photography as it is light, sharp and small. It also handles really well from small DSLR’s to my big D4. As you can see from the photo above, it looks perfect on my F3HP.

This gem of a lens is being sold really cheap these days because the faster f/2 and f/1.4 is more desirable for many people. You can use that to your advantage because a nice mint one can be had for around $100 here in Japan. People are so fixated with the fast aperture varieties that they overlook this lens and what it has to offer. People “in the know” will choose this lens for certain jobs because of it’s strengths.

(click on the thumbnails to enlarge)

The images (shot on ISO400 film) above shows this lens in action. The 35mm field of view is favoured by many street photographers because it is wide enough to show what is going on in the frame while not being overly wide as to distort the subjects and make them look unnatural. The picture with the grasshopper shows you how close one can focus with this lens (about 0.3m). The lens is also known to have unusually low distortion for it’s class so architectural photographers value this lens for indoor and outdoor photos. This is also a neat feature and can be used for portraiture as well so that your subjects won’t look like a piece of modern art.

IMG_2682Here is the lens together with it’s predecessor. The older one has a longer focus throw, the 5m mark is important to me for street photography. I usually shoot this lens set to 1-1.5m anyway but the 5m mark comes in handy sometimes. From this statement, you can easily tell that my photography style is a bit intrusive as far as personal space is concerned but compared to what Bruce Gilden is doing, this is nothing!


Disassembling this thing is pretty easy for an experienced lens “tinkerbug”. I can even say that this lens is also suitable for a beginner’s attempt provided that he has read a couple of guides and literature on how to service manual focus lenses.

The construction of this lens is typical of Nikkors of the same era and there are no surprises here. This lens is best opened beginning from the front and work your way until you have disassembled everything.

Since my optics are clean, I will not tackle how to work with this lens’s objective. This is for the people who want to overhaul the main barrel in order to re-lubricate their lenses and also clean it thoroughly while they are at it.

But since I value my readers very much, I decided to open up my 35mm lens’s objective just to show you how and where things were put together and with what tools.

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.

Disassembly (Barrel):

As mentioned previously, this is a pretty straight forward lens to work with and the goal of this section is to separate the objective from the barrel as well as to dismantle the barrel to it’s main components for a thorough cleaning.

IMG_2496Start by removing the 3 screws from the rear bayonet mount. You can remove the objective (optical assembly) without removing this part but it would be nice to see where the parts connect to help you later in reassembly.

IMG_2497.JPGAnd off the bayonet goes! Luckily for us, this lens is pretty simple and orthodox and Nikon did not use any weird spring and lever or cam assembly with this part.

IMG_2494.JPGTo remove the objective, simply remove this tiny set screw with a precision screw driver. Be careful not to lose this tiny screw or damage the head in any way. A bad set screw head will require special tools to be employed just to remove the stuck set screw.

While it is always advised to work with any lens while it is focused to infinity as a point of reference, you may occasionally need to focus it closer to it’s minimum focusing distance to reveal screws in the front barrel and this lens is no exception.

IMG_2495.JPGSimply unscrew the front barrel. If it does not come off easily then you may want to place a drop of solvent into the set screw hole to dissolve whatever glue or thread lock that Nikon has used on this part. I use acetone or MEK (methyl ethyl ketone).

This depression in the thread is where your set screw is sunk into. Be careful later during reassembly as you want the set screw to sit exactly where this depression is or else you will risk ruining your set screw.

IMG_2498.JPGAt this point, you can safely remove the objective from the main lens barrel. Be careful not to drop the objective on the floor! The objective is not held secure by any screw and there is a risk that it will free-fall to the floor if you are not careful.

If all you want to do is to clean the fungus in your lens or remove any junk inside it then I suggest that you do not go any further as disassembling the rest of the lens barrel is of no benefit to you. Go straight ahead to the next section.

IMG_2499.JPGThe aperture ring comes off easily since it is being held in place by the rear bayonet mount alone. I suggest that you remove this as soon as you remove the bayonet and not wait till this step like what I did here.

IMG_2500.JPGCarefully remove the rubber grip by running a rounded toothpick underneath it and gently go through it’s whole circumference. Doing this will separate this part from the focusing ring as it is likely being held by rubber cement.

Gently remove this part as you do not want to tear or puncture this part because this part is irreplaceable. There are replacement rubber grips out there but they will not look like the original and you will have to trim it down to fit.

IMG_2501.JPGWith that rubber grip out of the way, you can now access this little hole. I call these holes “reservoirs” as they are used for dropping in glue on the assembly process. Simply place a drop of acetone into this hole to loosen it up. It may take a couple of application and even several hours of waiting before this thing finally soften up so be patient.

IMG_2502.JPGWhile waiting for the acetone to do it’s work, I used the time to unscrew the chrome grip. Simply remove these 3 screws that secure the chrome grip. The picture above just show 1 out of the 3 screws.

IMG_2503.JPGThe chrome grip should come off easily, if it didn’t then just do the acetone routine on this thing as well. This part is sometimes held by superglue and it can be annoying to remove.

IMG_2504.JPGThe acetone has done it’s work and now the front ring can be safely unscrewed. You can use a pair of grippy rubber gloves to help you with this. Never force your way with these as you can risk ruining the threads on these parts

IMG_2506.JPGWith the front ring out of the way, you can now unscrew these 3 screws but before doing so please mark their position in relation to the other parts of the focusing ring as this part is a precision adjustment point. You will have to recalibrate this part later anyway but having the marks there will help remove a lot of guess work. This part is what you need to adjust to fix any problems pertaining to infinity focus later on during reassembly.

Again, always remember to work with any lens while it is focused all the way to infinity as a point of reference and make you marks or take your pictures while it is at this state. Take plenty of pictures or notes to guide you as there is no going back after this!

IMG_2507.JPGThe focusing ring can now be separated from the rest of the barrel. The 3 screws from the previous step holds down a thin brass ring that in turn secures the focusing ring into place by compression and pressure alone. I know that it sounds inadequate but it works.

IMG_2505.JPGNext, remove these 3 screw to remove the ring with all colourful the lines engraved in it. Please ignore the fact that the focusing ring is in the picture. I just left it there as a guide.

IMG_2508.JPGAnd off the ring goes. As with the chrome grip, this part may be held by adhesives as well so do the acetone routine on this part if it doesn’t come off easily.

IMG_2509.JPGYou can now access the helicoid keys once the ring is gone. Be sure to document and mark the parts while the lens is set to infinity. On my lens, this is the configuration and position that I should have when I reassemble the lens in order for my lens to focus properly all the way to infinity..

Remove the 2 screws inside the circular holes to free the helicoid key. The helicoid key is in charge of keeping the helicoids in position as you rotate them in order to achieve proper focusing as your lens expands and retracts.

IMG_2510.JPGThe helicoid key is now free. Notice that it is mounted in reverse as you can see from the previous picture. Also notice that I have marked the helicoids in their infinity position. I had to rotate the inner helicoids a bit to free the helicoid key so the mark did not line up in the picture above.

Before going to the next step, please read my post regarding how to work with helicoids as this step is the most critical when it comes to disassembling the main barrel. If you got it wrong then you can be sure that you are going to have a stressful time guessing where they should mate and align.

IMG_2511.JPGIt’s time to undo the helicoids. This is where my main helicoid separated and I marked the position in relation to the outer helicoid’s infinity line.

IMG_2512.JPGAs with the main helicoid, I marked the position where the inner helicoid separated with a simple mark in the shape of an arrow. These marks serve as guides for me to know where I should align them later during reassembly in order for the helicoids to be aligned properly and achieve infinity focus.

IMG_2513Oh, I forgot about the aperture fork! Simply remove the tiny pillar screw and you can safely remove this. The pillar screw is not in the picture but it is screwed to the hole in the fork’s ring (check the picture). The pillar screw slips into a notch in the aperture ring and it is the only thing that connects the aperture ring to the aperture fork.

Disassembly (objective):

As previously mentioned, the optics look OK so I have no need to open this thing up so do not expect a complete teardown. I will just dismantle it to the point where it is easy to for you to understand how things were put together. Don’t fix what is not broken.

Be careful with putting the optics back together because if an element is facing the wrong way then you will have to re-open this thing up to fix that. To avoid that, I use a pencil to mark the edge of my elements with a small line pointing to the front of the lens. This way I can be sure that my elements are facing the correct direction when I reassemble the lens.

IMG_0590Remove the front optical assembly from the objective by means of a lens opener. Be really careful not to damage the front element!

IMG_0592Now, use a lens spanner to remove the retention ring that secures the front element to the rest of the assembly by positioning the lens opener’s spikes on these 2 depressions. Also note that this is glued on my example so do the acetone routine for this part before you go ahead or else you will risk damaging your lens.

I am not going to open this part up but it should be pretty straight forward and if you have been following my blog then you will already know what to anticipate. Use a lens sucker to remove any elements from here on.

IMG_0591The rear part of the front optical assembly can be twisted off easily with your bare hands. You can then access the other elements on this part after this point.

IMG_0588The rear elements assembly can easily be removed by unscrewing it.

IMG_0589To access the other parts of the rear elements assembly, simply use a lens opener or a lens opening compass to remove the retention ring.


Working with this lens is a fun exercise. It can be a little bit frustrating when it is time to put the objective back into the barrel because there is very little room inside the lens but it can be done in under 5 minutes after several tries.

Before you put the objective back, be sure to reassemble the barrel completely including the bayonet mount but leave out the front ring of the focusing ring so that you can adjust the infinity focusing of the lens.

Carefully slide the objective into the barrel and make sure that the aperture fork and stop down lever mated properly with the small tabs in the objective. Focus the lens all the way to infinity and then mount it on a camera. Focus on a far away structure about 2 kilometres away or further so that the focusing indicator on your camera lights up. This is your correct alignment for your infinity point.

With your lens is that position, check and see if the infinity mark is dead centre with the line on the lens’s focusing scale. If it is not, then loosen the 3 screws inside the focusing ring and then lightly turn it until the infinity mark is squarely aligned with the centreline. Failure to do this will result in a lens with an inaccurate focusing scale and will prevent you from focusing to infinity accurately. It’s either you lens will focus past infinity or it will not focus to infinity at all and this will also affect the other distances as well so get this right.

Also, do not forget to lightly lubricate the aperture fork and stop down lever with the same grease that you used for the helicoids. All you want is a very thin film of grease or else your iris assembly will end up being oily or dirty and that is going to be a bigger problem for you since iris assemblies are always annoying to fix.

Also do not forget to lubricate the aperture ring’s ridges underneath the ring for a smooth and precise aperture clicking action. You will want to lightly lubricate the aperture ring’s inner edges (that comes in contact with the barrel) so that it turns smoothly.

I use a heavier grease for this lens as the lens was initially lubricated with a lighter grease. The focus throw of this lens is short so a heavier grease will make my turns more precise. This is a matter of taste so it is up to you wether you want feather-light focusing or a heavy but precise focusing.

Thank you very much for your time and I hope that you have enjoyed this blog post. Until next time, 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.


6 Comments (+add yours?)

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  5. Leon R
    May 20, 2018 @ 18:26:38

    Hello Richard Haw,

    this is a stunnig website you‘ve built here.
    I‘ve got a problem with my Nikon Nikkor 35mm f2.8 Ai-S. When I turn the focus ring to the hard stop at infinity, the actual focus doesn‘t turn all the way up to infinity. So in practice, objecta more than about 100m (or less?) away won‘t appear in focus. I‘d have to turn the focus ring even further, but the hard stop is already reached. I haven‘t found anything on the internet on how to fix this. As everything else works smoothly and I haven‘t ever opened a lens, I‘d consider it too risky to just disassemble it and try to find a fix.

    Is there any way you could help me on this? Is there an easy fix, a part I could adjust?

    Help much appreciated

    Best Regards


    • richardhaw
      Jun 21, 2018 @ 16:17:47

      The problem is with the focusing scale. it’s a very easy fix and I wrote a whole article on how to calibrate it. Search for it using infinity calibration as keyword. Ric.


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