Repair: NIkkor 135mm f/3.5 Ai

Hello everybody! I’m now busy with fixing Contax cameras for the coming series I’m preparing for you. Contax rangefinders are very nice cameras and they are cheap if you compare them to Leicas and Nikons. They’re cheap not because they are bad but it is all about market perception. If you want great value today for old rangefinders then it’s difficult to beat a Contax. They’re better-built than most cameras of the era but it also lacked some important features which ultimately became the last nail in its coffin. Despite that, they’re great cameras and they are very cheap now. Today, I will show you a lens that is also very cheap but performs admirably for every day use. Very much like the Contax rangefinder cameras, they offer great value for what you pay for and they’re also much simpler to service unlike the Contax which has a reputation for being difficult to service and very time-consuming so some repairers won’t even touch them. Read on.


The Nikkor 135mm f/3.5 Ai is the first major update of the excellent 135/3.5 family. It has remained almost unchanged optically since the Nikkor-Q.C 13.5cm f/3.5 RF debuted. While the optics were slightly tweaked over the decades that followed, the old optical design remained largely unchanged despite the move from S-mount to F-mount until the lens in this article appeared. The Nikkor 135mm f/3.5 Ai introduced a new optical design, it now has a 4-elements-in-4-groups design and it is no longer a Sonnar-type lens like all of its predecessors. I am not sure what the benefits are since all the older F-mount versions are great like the Nikkor-Q 135mm f/3.5 Auto. This is a tough act to follow so I am sure that this upgrade has something significant to offer. Sonnar-type lenses have their quirks despite being great performers and focus-shift is one them to name a few so this may be one of those things that were fixed with this version.

IMG_1510The Nikkor 135mm f/3.5 Ai lens is a good-looking lens and I like it because it’s a practical focal length for general use. It’s also small and light so it doesn’t take a lot of space in the bag. The styling is also in-tune with the Ai lenses’ styling.

IMG_1511The glass is dirty but it’s in good shape. There are some fungus inside but it’s not that bad and the most important thing is the coatings are still OK. Good thing I got to this lens and I can prevent the fungi form growing even worse.

28275649_10155214106061911_1747990436_o.jpgThe lens is well-built and feels solid in my hands. It’s well-balanced and it handles very well with whatever camera you mate it with. Here it is with the lens shade deployed, this is the first time this feature was implemented in this lens family. It’s a handy feature and it makes the lens even more useful because you don’t have to bring a separate accessory with you. It’s also small then its predecessors which are all kind of long as far as small prime lenses go.

The Nikkor-Q 135mm f/3.5 Auto is already an excellent lens to begin with and the earlier New-Nikkor version is just a cosmetic upgrade. The good news is this lens is just as good as the ones that preceded it, if not better. This lens family is characterized as being great performers even wide-open, has decent bokeh quality and relatively good flare resistance. Check my pictures to see what I mean.

HAW_1885I don’t really care much about these kinds of pictures but for people who care, this lens is typical for a telephoto lens as far as distortion goes. It has a slight pincushion-type distortion and you can see it if you look very carefully at pictures like this but is insignificant when you use the lens in more practical applications.

HAW_1904There are some chromatic aberration in this picture but you will have to look hard to see it. I recall that the older lenses suffer a bit from this so maybe this new optical design remedied this. Notice that this picture has a nice “3-D pop” to it.

(Click to enlarge)

The pictures above were shot from f/3.5, f/5.6 and f/8 respectively. As you can see, it’s not a lens for bokeh lovers but this still has decent enough bokeh to satisfy you. The results at f/3.5 look very good. The picture is very sharp where focused and the rendering is smooth and refined. The trade-off is you get some vignetting but that is unavoidable when shooting wide-open in most lenses. Stop it down to f/5.6 and you won’t see much difference in terms of character but it does improve a bit when you look closer and the resolution is also much better. The bokeh balls also look polygonal now and it’s very typical of this lens to do this as it only has a 7-bladed iris. Stopping it down to f/8 will make the lens perform at its peak, although you really will not notice much compared to f/5.6 because the lens is already very good wide-open. You gain resolution and DOF as you stop it down, the chromatic aberration also goes away by f/5.6 and up. This all sounds boring but this is what the lens was calculated for. A lens that changes character as you stop it down is desirable as an artist’s tool because it has more artistic potential than a lens that looks roughly the same in all f-stops. This lens has its uses and it certainly filled that very well and that is to cater to the lower-end of the market where people would buy it for its performance wide-open and wouldn’t care much for the balance and delicateness of the rendering. This overcorrection has became prevalent these days due to charts and all the pixel-peepes so the AF-S Nikkor 58mm f/1.4G had to be designed to bring this back. It was a very bold move by Nikon to introduce this lens at this age to remind people that charts and numbers aren’t everything in lens design, it’s first and foremost an artistic tool and not something that’s made for engineers to test charts with. Well done, Sato Haruo-san. It is a very special lens for people who cherish the more refined characteristics of a lens. It was designed by him with this vision in his mind.

(Click to enlarge)

This lens is pretty good for candid shots. It can be hard to focus when using it for street photography because of the 135mm focal length and the f/3.5 maximum aperture is also not very helpful in acquiring focus. Notice that the lens has a very pleasing and natural character to its rendering, definitely a lens with that “classic look”. The picture of that lady with the sunglasses was shot at f/8 and this lens is excellent at this aperture. It is also a great lens for train-spotting for those who are into this kind of photography but it may be a bit too short since most people use longer lenses to shoot trains for safety.

Let’s now see some pictures that were shot with film. This lens was calculated to work with film since it was the only medium for this lens back then. Seeing how it renders with film will give us a better understanding of how it renders and seeing results from both film and digital can help us assess a lens’ performance better. Film also has a unique look that you won’t get using a digital camera because of grain and how light works with chemistry as opposed to a sensor capturing light and this makes it an interesting exercise to observe a lens’ rendering with film. I took these photos with a Nikon FG and Fujifilm Industrial 100.

You will find that this lens renders beautifully with film. The colors look great and sharpness is excellent. Skin tones look great and natural, while this may also be attributed to the film stock used the lens also has a big role in rendering a picture. You will not get the subject isolation qualities of a faster f/2.8 lens with this but it’s decent enough to blur what you don’t want in your frame so long as you position your subjects properly.

Despite being having a maximum speed of f/3.5 you will notice that it can be hard to get more things in-focus and you’ll miss a few times just like what you see here. What can complicate things is the maximum speed is somewhat slower than usual your viewfinder will get a bit dark and it can be difficult to acquire focus specially if you’re using a split-prism. This can also happen in bright conditions but is most obvious in darker conditions.

You are rewarded with a beautiful photo if you nailed your focus properly. Even small details such as the fine strands of hair on the lady’s forehead is visible despite me using a film that’s not known to be fine-grained. The quality of the bokeh is smooth, a cheap over-corrected may have the tendency to render foliage terribly but you don’t see that with this lens.

Tracking moving subjects can be difficult with a manual lens and it requires some practice to get used to. It will help develop your discipline and patience, 2 qualities that photographers were used to be known for. The focus throw of this lens is a little bit long for my taste but it’s not a problem at all and I have used lenses with even longer focus throws than this. I would prefer a slightly shorter throw than this but that’s probably asking for too much.

Notice how delicate the skin is rendered you don’t get any harshness and the tones are so natural. The little imperfections and how grain looks help make this picture look unique.

You can consider this to be the “poor man’s portrait lens” because of its price but there’s nothing poor about how it performs. I love the 135mm focal length for tight framing but there will be times when it’s not long enough so here’s a 2x crop. If this shot was taken with a digital camera you would have seen sharper details in this picture.

(Click to enlarge)

Here are more pictures from that afternoon, click on them to see the larger versions. This is a really neat lens, it’s usefulness is obvious and it’s certainly a great performer on both film and digital. You can’t go wrong with this lens.

This is a great lens for travel photography as it’s light and compact. Pair it with a New-Nikkor 50mm f/2 or a Nikkor 28mm f/2.8 Ai and you get yourself a very good combo. I recommend this lens to everyone because you will always find a situation to use it and your money won’t go to waste. It’s one of the best things you can buy for about $50 (in decent condition) online and it will be one of your favorite lenses when paired with a smaller Nikon camera.

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. Please also read what I wrote about 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 novice. Before opening up any lens, always look for other people who have done so in Youtube or 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.

Disassembly (Lens Barrel):

The lens barrel’s construction is straight-forward but I’ll caution you about the glue that Nikon used on this lens. Nikkors made around the ’70s are notorious for this so I always approach them with caution and a lot of solvent. If a screw is stuck, just heat it or use acetone or alcohol to soften the bond first before attempting to remove it. I find this a bit surprising because for a low end Nikkor, this lens was well-made and the parts or construction reminds me more of the high-end ones of the same vintage. This is a nice lens for a beginner to work on provided he has the right tools for the job. If you don’t have the right tools when do not even bother working with this lens.

IMG_1512Locate a tiny grub screw near the front ring using this access hole on the hood. Not sure if yours has more than 1, I remember that mine only has 1 grub screw.

IMG_1513Now that the set screw is gone, you can now remove the front ring. If it won’t come off easily, place a drop of alcohol along the seams of the front ring via the access hole. This is usually sealed at the factory using lacquer and contact cement at times. I also suspect that repairmen are the ones using contact cement because that is overkill for this purpose.

IMG_1529The front ring can be further disassembled into these 2 parts. The name ring is screwed to the front ring and there are lots of dirt underneath it.

IMG_1514Once the front ring is gone, you can now remove the shade. There felt in the shade had to be replaced on mine. I used a very thin velvet for this, the material cannot be too thick or else the shade will be too tight.

IMG_1515These are the places where I found the grub screws. There is another one that you has to be removed before we can proceed, look for the grub screw that’s closer to the lens body and remove it. This is the one that is securing the front barrel.

IMG_1516The front barrel can now be safely unscrewed-off the lens barrel.

IMG_1517The objective can now be extracted. Since the front barrel is the one securing this thing, it is very important to never face the lens towards the floor or else this thing will fall to the ground and you will surely damage the glass so be careful.

IMG_1518Let’s now head to the other end of the lens barrel. Remove these screws so you can get to the inside of the lens barrel. If you are new to this, be sure to read my guide about how to deal with screws on the bayonet mount. Many people get stuck with this process because they used the wrong type of screwdrivers so here’s my article about screws and drivers.

IMG_1519The bayonet mount can now be safely removed.

IMG_1520The bayonet assembly can be further disassembled into these components. I had to clean my lens thoroughly so this had to be done. Be careful with the tiny screws on the bayonet because one of them is different. The screw at the 6 o’çlock position is the one that is preventing you from damaging your camera when you mount a lens to it so make sure that you don’t damage or lose it!

IMG_1521Before you can remove the aperture ring, you will have to remove these 2 screws.

IMG_1522Those 2 screws secure this aperture coupling fork. This is the mechanical linkage to the iris inside the objective.

IMG_1523The aperture ring can now be safely removed.

IMG_1524To remove the focusing ring you’ll have to remove the rubber grip. Use a toothpick or a small screwdriver and run it around the grip’s circumference to lift it from the glue. Be careful not to rip or tear this thing because these can be delicate.

IMG_1525The focusing ring can now be removed by unscrewing these screws but before doing that make sure that the lens barrel is set to infinity and do your best not to move it from that position. I always work on a lens while it’s focused all-the-way to infinity as reference. It is very useful so I will have a point of reference later during reassembly.

The upper lip of the focusing ring can be separated if I am not mistaken. I left it alone so I won’t have to remove it using a lot of force. These are usually glued with contact cement and it can be difficult to remove at times. Soaking this thing in an alcohol bath will help a lot to soften the cement. It’s not essential for you to remove it so just leave it alone.

IMG_1526The focusing ring can now be safely removed.

IMG_1527Assuming that your lens barrel is still turned to infinity, make some small marks to remind you how it should align. This will help you a lot later to determine if you reassembled your lens correctly or not.

IMG_1530The shiny grip and sleeve can be removed by extracting 3 screws at the lower part of the grip. These are sometimes stuck due to dried-up grease or glue, if yours is stuck just drop plenty of solvent like alcohol onto the seams to soften it up before you pull this out.

IMG_1532I took another picture of the lens barrel before I separate it into its bare components just so that I will have another reference picture for later.

IMG_1531The helicoids are being held-together by the helicoid key. The helicoid key is secured by these 3 screws, they can be hard to remove at times because they’re glued. Nikon used a tough epoxy-based thread lock during this era. If yours won’t come-off easily, heat these with a soldering iron or miniature torch and try unscrewing it while it’s very hot. I hate these screws because there are times when they would snap and I would require a screw extractor bit to remove what’s left in the holes so be careful and go at it slowly.

IMG_1533The helicoid key keeps the helicoids in-sync so when you turn the main helicoid, the two other ones will turn at the same rate. This will extend or retract the lens barrel and this is how your lens is focused.

IMG_1534Now that the helicoid key is out, you can separate the outer helicoid from the central one but don’t forget to mark where they separate because this is also where they should mate when you need to reassemble them later. Read my article on how to work with helicoids so you won’t get stuck later during reassembly.

IMG_1535Before you separate the main and inner helicoids you will have to remove this metal guide. This prevents you from over-turning your focusing ring and sets your lens to only rotate within its focusing range, constraining it to its focusing range. There are a total of 3 screws if I recall it correctly.

IMG_1536Before removing it, make sure to mark which way should be facing forward to help you remember how to put it back properly later.

IMG_1537You can now also remove this brass ring. This brass ring is what the three screws on the focusing ring is screwed to. You can adjust how your lens focuses to infinity by adjusting the focusing ring later and this thing should also turn to allow you to do it.

IMG_1538You can finally remove the helicoid stop. It is hits the the guide that we removed a while ago and you can adjust it by tightening it with these screws. This is also important so that the lens will stop turning once it hits infinity. You will have to adjust this along with your focusing later after you reassembled your lens.

IMG_1539Separate the inner helicoid from the main one and never forget to mark where they part!

That’s all for the lens barrel. There seems to be more parts involved than usual but so far it’s still an easy lens to take-apart for an experienced repairman. Clean everything well, I also advise you to use a lighter type of grease for this because a stiffer one will just make this lens difficult to turn. Make sure that there are no traces of old grease on the helicoids and you will have to pick it with a toothpick if you have to. It’s tragic to find out that your helicoids are gritty after you have greased it and then you will have to clean it again. Just do it properly the first time and that will save you a lot of time.

Disassembly (Objective):

There is nothing special about the construction of the objective, its design is conventional and there’s nothing complicated or difficult about it. I didn’t clean the iris because mine is clean but if yours needs to be cleaned then I am sorry that I don’t have the information in this post. Please see my other articles to find clues on how to work on the iris if you have to.

IMG_1540The rear assembly can be separated from the main housing just like this.

IMG_1541And it can further be disassembled by removing this collar.

IMG_1550The rear element can be removed by removing this retention ring. Use a lens spanner to remove this ring. If your lens spanner can’t reach the slots then bend the tips outwards so the tips of the spanner can reach them.

IMG_1551The rear element can now be safely extracted with a lens sucker. Make sure to take note which side should be facing forward, putting a lens element back facing the wrong way can do damage to the lens when you reinstall the retention ring because the curvature will not match the housing’s inner lip.

IMG_1542The front elements assembly can be unscrewed from the objective’s housing just like this.

IMG_1543The front element is secured with a collar. Be careful not to drop this to the floor.

IMG_1544Extract the front element with a lens sucker.

IMG_1545the last element on the front assembly is sealed to its collar. It’s best not to remove it or if yours isn’t glued to it then be careful not to drop it. It’s sometimes held in place with a type of paint which is most likely enamel-based and it can be flimsy at best.

IMG_1546Remove this collar to reveal the retention ring of the inner element.

IMG_1547The retention ring can be removed by using a lens spanner. Notice that mine is wet with alcohol, it was secured with lacquer at the factory and alcohol with easily dissolve it.

IMG_1548Carefully remove the ring and make sure you don’t slip and damage the glass.

IMG_1549The 2nd element can now be extracted. This can be a tight fit at times so don’t force it.

The only thing I hated here is the amount of lacquer used to seal it. I am not a very patient man so I hate it when I have to wait for the alcohol to soften the bond before I work on something. When putting the elements back just make sure that they’re all facing the right direction. The lens is simple enough with only 4 elements in it but you’re advised to take note of the orientation of all the elements just for good measure.


This lens took me more time than expected because of all the parts involved but it was a nice experience so far, a great project after a hard day’s work at the office. There are few things that can go wrong here so long as you took notes and references to aid you later in reassembly. Before you call it a day, there are still some things that you should do with it.

You must calibrate your lens so that it can focus properly at infinity. If you haven’t read my article please read my guide on how to calibrate a lens for infinity focusing. The article has lots of information for you on how to do this for most Nikkors. Make sure you have rebuilt it properly before you attempt this or else all your efforts will go to waste so test it first and  see if everything is working as they should. This is usually the last step involved.

IMG_1555Reassemble your lens up to this point. Leave out the focusing ring and the hood for now.

IMG_1553Adjust your lens’ focusing range with this. Make sure that your focusing stops exactly at infinity. This is very important so your focusing scale will be as accurate as possible. See if you are satisfied with the results and then tighten these screws and apply a dab of nail polish to seal these 3 screws to prevent them from moving accidentally.

IMG_1556You can now reinstall the focusing ring. Make sure that the infinity sign is centered with the white line then tighten the screws to secure the focusing ring. I sometimes apply nail polish or thread lock to the threads of these screws to prevent them from moving.

IMG_1557The shade is bent and warped from damage. This is difficult to fix but we can get it back to being circular again with patience and some effort.

IMG_1563I have a circular cut of brass for this kind of problem, I use this as my anvil.

IMG_1564A rubber mallet is also handy for this kind of job.

IMG_1566After hammering it for some time, I got it to be as circular as I can. The tough part is the front edge of the hood because its lip is beveled. I do not want to hammer it too much or I will flatten the lip and make it even uglier than when I started doing this. At least it can now be positioned without effort unlike before where the ding is obstructing the shade’s path. I can live with this since I am not meticulous anyway. The lens is also clean now, it is now free from grime and fungi.

Did you enjoy this? I am currently exhausted but I had to rush this because I know people will be checking my blog tonight to see if I published a post. It’s important to me and I treat you and this blog with utmost importance so I cannot let you all down. I am currently involved with camera repair because I want to begin this new article that I am preparing for you and for it to work properly I have to write a couple of things before I tackle the main topic. I always have my readers in my mind so I’m spending extra effort and time just to make sure that you’ll understand what I am about to show you. It’s very important to put things in-context both historically and technically before I show something complicated because I am aware that the majority of you aren’t really into camera repair. See you guys next time, I am now preparing myself physically because I am about to cover 2 big events for you in the coming week, I need the stamina and time for it so wish me all the best. See you guys again 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, you can simply make a small pledge 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.

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Helping support this site will ensure that it will be kept going as long as I have the time and energy. 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.

5 Comments (+add yours?)

  1. Trackback: Repair: Nikkor 50mm f/2K (New-Nikkor) | Richard Haw's Classic Nikon Repair and Review
  2. Trackback: Repair: Nikkor-Q 135mm f/3.5 Auto | Richard Haw's Classic Nikon Repair and Review
  3. John.
    Jul 12, 2019 @ 18:32:02

    Would love to see disassembly of the Nikon 135 2.8 manual lens to clean and lube the shutters thanking you very much. John.


  4. Trackback: Repair: Nikon FG | Richard Haw's Classic Nikon Repair and Review
  5. Trackback: Repair: Nikkor 135mm f/3.5 Ai-S | Richard Haw's Classic Nikon Repair and Review

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