Repair: Nikkor-Q.C 5cm f/3.5 (LTM)

Hello, everybody! I just spent $8 on a small cup of coffee. It was exquisite and it’s smooth, rich and refined. It also doesn’t leave a harsh after-taste in your mouth or throat just like what many cheap instant coffees tend to do. I certainly appreciated it but I won’t drink it regularly because I can just use that amount to buy me a decent lunch. I will assume that many people will do the same and some people won’t even think of spending that much for coffee. I’m not an expert on coffee but I do appreciate a good cup. Today, I’m going to introduce to you a lens that’s only appreciated by people who know their lenses and the going price for these things today will turn many people off. It’s a very special lens and it has a special part in Nikon’s history. Please read the article to find out what that is.


This is the Nikkor-Q.C 5cm f/3.5, a rare lens that not many people knew about. It’s Nikon’s version of the then-popular Zeiss Tessar and its simple 4-elements-in-3-groups design is a near-identical copy of the Tessar design. This design is one of Nikon’s oldest lens designs, it was first used on the 1935 Hansa Kwanon if I am correct and it was popular until some time in the early 1950s as a cheaper alternative for shooters looking for a 50mm Nikkor. This is the later “rigid” version, the earlier one is collapsible and is considered to be rare. I would love to own one of those but they’re not cheap. Apart from the barrel design, you can consider both lenses to be the same since they share the same optics. This was made in the mid 1950s to “refresh” the older collapsible version’s design so Nikon can stretch its profits from this old but tested lens design. This particular version wasn’t made for long, it was only made for about a year or so compared to the collapsible version which saw a long production life since 1940 and sold in numerous versions. The unusual thing is that this is easier to find these days on the used market compared to the collapsible one and it costs much less, too.

IMG_9545The lens barrel design in unique amongst Nikkors, you can easily recognize it because of its pudgy look. The long post you see here is used for constraining the focusing ring so it’s not going to turn beyond the lens’ focusing range since it’s in the way of the infinity lock. The lens has a special feature in that it can extend beyond its focusing range wherein it’s now de-coupled from the camera’s rangefinder. This will allow it do “macro mode”, that’s something that it shares with other Nikkors like the Nikkor-H.C 5cm f/2 (L39). You cannot use the rangefinder to focus in this mode and you must focus by measuring the distance between your subject and your film plane which is conveniently indicated as a red dot or a black circle with a horizontal line slashed across it. I am not sure if other brands offer this feature as well but it’s certainly one of the things the LTM Nikkors are known for.

The lens feels dense because it was made using brass and plated with chrome. Its weight gives you the impression that it’s a well-built lens and it also helps make your setup a bit more stable. The distance scale and other engraved details are beautiful to look at but it’s a bit cumbersome to use this lens because you will have to look at the front of your setup just to see the DOF and distance scales. The first generation of Leica lenses mostly have it like this and this is why I prefer the Contax system from Zeiss. The aperture ring does not have click-stops to indicate which aperture you’re and it can be easily turned by accident so keep an eye on it before you take a shot. Click-stops on lenses weren’t implemented in the early years of 35mm photography and it was considered to be a novelty back then.

IMG_9640It’s a tiny lens compared to what we’re used to seeing these days and the Nikon Z6 makes it look like a miniature. The truth is it’s one of the bigger L39 Nikkors under 50mm but it is smaller than the Nikkor-H.C 5cm f/2 (L39) which is almost 2x bigger. Its construction is simple because it was marketed as a cheaper alternative to Nikon’s more expensive lens variants so people on a smaller budget can also buy a 50mm Nikkor.

Let’s study how this lens performs when shot with film and digital. Knowing how a lens performs will help you maximize it as you work-around its weaknesses and use all of its strengths to help you create the picture that you have in your mind. You can also use its flaws to your creative advantage by incorporating them into your pictures to give it that unique look that many people are into these days.

(Click to enlarge)

The pictures above were shot with the lens wide-open and stopped-down to about f/8 or so to give you an idea of how this lens performs. Wide-open, you will notice that there is some vignetting at the corners and it won’t really go away even if you stop the lens down to a small aperture like f/5.6. This will be a problem if you shoot pictures with the sky in your frame. Sharpness and contrast is very typical of a Tessar-type lens, the center shows nice sharpness and contrast even wide-open and it improves a lot upon stopping it down. The corners are poor compared to the center which is a signature of Tessar-type lenses, it is a “feature” that was deliberately-designed into the formula because it helps show how good the center is. This is the defining trait of a Tessar and any lenses that were derived from this design. The performance didn’t change by much whether you’re focusing close or at infinity. The character of the bokeh is somewhat “chunky” and isn’t as smooth as the bokeh of a Sonnar-type lens. This hints that this lens is overly-corrected somewhat to give you high sharpness wide-open at the expense of the character of the bokeh. It’s not bad at all to be frank and I wouldn’t call it ugly. In fact, it adds a certain character to the images this lens produces. Sphero-chromatic aberration is not really a problem with this lens at all even wide-open which is a good thing.

DSC01350Here’s another sample of the “chunky” bokeh that I was talking about awhile ago. I took this picture using this lens’ special “macro mode” feature to exaggerate the effects of the out-of-focus characteristics (bokeh) and also to see how it performs up-close. It’s still good but I can see a small drop in performance. I am not sure where to attribute it to but I will just speculate that this lens wasn’t calculated for being used like this.

(Click to enlarge)

Flaring can be terrible with this lens because of its old coatings but you won’t see plenty of ghosts as this lens only has 4 elements and the Tessar design seems to be rather good at countering this. There is a weird artefact that can appear when shooting against very bright sources of light such as the sun. Many old lenses with out-dated coatings will show this effect such as the Nikkor-T 10.5cm f/4. I find that distracting but I’m sure that others will find a use for this. The sun-stars look great because of the preset-type iris.

DSC01342Here’s a picture demonstrating how Tessar-type lenses have nice centers but the corners look terrible (by-design). I don’t really mind this but you will have to keep this in-mind as you use the lens. Position your subjects at the center of your frame and you’re good.

DSC01345Subject separation is not something that you will notice much with a lens in this class. If your subject is further-away from you then you’re not going to notice this effect at all.

DSC01364If your subjects are closer to you then you’ll get more separation. This lens is great when shooting at closer distances even wide-open. Notice how nice the details of the cardboard fish is and how it “pops-out” of the frame in a 3D-like manner. Resolution isn’t so bad too considering that this was shot wide-open.

DSC01372The colors look nice and neutral so far with only a very slight hint of blue. I don’t know if you noticed something from the pictures that I have been showing you but if you didn’t, I will point it out to you now. The colors look rich and the contrast is unusually-high for an old Nikkor from the rangefinder-era. This is also another trait of the Tessar that I love so much, see how nice the reds look like and how rich the blues are despite the scene being shot in a not-so-sunny side of town.

(Click to enlarge)

Here are some more pictures that I took with this lens. It certainly has that nice feel to the pictures in the sense that it has that “vintage look” that many people are into these days. I know that this is subjective because you either hate that look or you like it.

Now that we have seen how this lens performs in digital, it’s now time to see how it looks like when shot with film. I used Fujifilm Industrial 100 film for these pictures and I used a Nicca 3S as the camera. This setup is probably how many people used this lens in its day and this will give us a more “authentic experiece” when using this lens. We take pictures that were shot using film to see how it performs with it because it was calculated during the film days and this is the only way we can see how this lens performs as envisioned by its designer.

(Click to enlarge)

These pictures show the (old-style) Tessar characteristics really well. The center is sharp but the corners are so-so. It was originally used on many low-cost lenses because Tessars offer nice performance around the center even wide-open and its very simple (but slow) design makes it perfect for a certain segment of the market where cost-to-performance ratio is an important factor. Its slow maximum aperture and its bokeh are trade-offs that many will happily ignore. “Bokeh” in the modern sense and how people use it these days is a recent concept. It didn’t become “a thing” until about 18 or so years ago and Kai from the Digitalrev videos also contributed a lot to this.

(Click to enlarge)

Stopping this lens down will give you nice colors and details. Shooting it with film makes it even more special, there’s something about this lens when used with film that you can’t see when shooting it with digital. You get rich, saturated colors and the contrast is great. I love the results I get from shooting with this lens on a sunny day using film. You can also see that there’s a bit of distortion on the horizontal lines in the picture but it’s not bad.

(Click to enlarge)

Using this lens in the correct setting will give you nice pictures with plenty of “character” and rich “atmosphere” which adds what we call “layering” in our profession. It adds a lot to your composition and also adds another layer of intangible quality that makes it stand out from other pictures. This is the vintage-look that many people are so into these days. The term “layering” is just an artist’s way of saying how a picture is “layered” into several sections divided by depth with each layer having a distict feel or elements that separates it from the rest.

(Click to enlarge)

Here are some more samples that were shot using film. You can see from the photos that this lens has something special despite all of its “flaws” or limitations. It makes for a good walk-around lens for any L39 camera because of the mentioned characteristics and it’s a very small lens that goes well together with the small Barnack clones. I am really liking it a lot and I will use it more these days.

So, what did you learn from the samples that I showed you? Do you think that this lens is worth buying? These things don’t come cheap these days and they are usually being sold for about $300 or so. I got mine for about $90 only because it was sold as junk. A collector will probably have one in their collection by now and casual shooters will want to buy a good sample of the Nikkor-H.C 5cm f/2 (LTM) instead because it’s faster and usually costs much less than this lens. This is a special lens and only people who love Tessars will be enticed to buy and use this lens. This lens is just one of the options that a Leica shooter is given when they want a Tessar because I don’t believe that Leitz made one since this was made by Zeiss and copied by nearly everybody who made lenses outside of Germany. Its price will turn many people away because the cheaper Japanese or Russian clones are a lot cheaper than this but they’re not made as well as this lens and they certainly don’t do that macro mode trick since most of them are of the collapsible type. That’s it for the lens’ introduction and review. It’s time to proceed to the repair section!

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 (Focusing Unit):

This lens was made during the early years of Nikon so it’s a simple design. It can easily be separated into 2 basic assemblies and I will show you how to do it in this section. Just like most lenses you see in my blog, you will want to separate the optics first so you can work on the rest of the lens without worrying about damaging anything delicate and that’s the first thing that we will do. This is the easiest part of the article but it gets harder as we go further. If all you want is to lubricate your lens then this is all you need to do.

IMG_9546Just like many Nikkors that were made during the early years, this lens can be separated into its basic components by removing a retention collar at the rear. Make sure that you focus the lens to infinity and do your best to keep it that way while you’re working on it.

IMG_9547Keep the lens facing down while doing this and make sure that it’s sitting safely on top of a stable and flat surface. This collar is the only thing that’s keeping the heavier-half of the lens from falling so make sure that you keep it safe while you remove the collar.

IMG_9548You can then remove the focusing unit fron the front part of the lens. See what I mean? It can drop to the floor if you’re not careful when you remove the retention collar. Store its front barrel assembly in a safe place while you work on the focusing unit.

IMG_9565The focusing unit can be easily removed by unscrewing 3 of these small grub screws. The focusing ring can be adjusted so you will probably want to mark its orientation before it is removed. I didn’t bother with it because I will adjust it later anyway but it is not a bad idea to mark its position so you will have a good starting point later.

IMG_9566The focusing ring can be easily removed just like this.

IMG_9567There’s no point in disassembling the focusing any further. Just clean it very well using a lot of alcohol and Q-tips or soak it in an alcohol bath to kill the germs or soften anything that has hardened like old grease. Mine was really oily as the old grease had deteriorated and its oil has separated from the soap base.

IMG_9568The helicoid for this lens is easy to work on since it only has a set instead of the usual 2. I took some notes on where they separated so I will know where they should mesh. If you are new to lens repair, please read my article on how to work with helicoids to make sure that you don’t make the usual mistake that many beginners do and get stuck.

IMG_9569Clean the helicoids very well to make sure that the fresh grease won’t mix with anything foul and contaminate it. I cleaned it with a brush and a coarse plastic kitchen sponge, the helicoids were then picked with a wooden toothpick to remove anything too hard for the sponge to remove. I tried mating them to see if they turn smoothly and thankfully I didn’t have to lap them this time to remove any corrosion.

I use the best grease available to me and chose one that’s not too thin but too thick so it’s easy for me to turn this lens. This lens has a long focus throw that’s typical of lenses from this era and using a thick grease with more resistance than I wanted will make it difficult to turn and cause me to lose a shot. The thick grease can potentially cause an accident to happen because the torque can potentially loosen the lens from the camera. This lens is of the older type of L39 lenses with no locking pins, you see many screw-mount lenses in the junk section with dented front rings because they were dropped and it’s easy to link that with this. This is the reason why a bayonet mount is the best way to mount a lens to a camera as it’s more precise and secure.

You will also want to apply a little bit of grease to the small bearing-ball in the inner part of the focusing ring because that thing is responsible for the click that you feel when you focus the lens pass the rangefinder’s focusing range in close-focus mode. Greasing it will make sure that the click feels smooth and the parts involved doesn’t wear easily. Do not dismantle the mechanism for the clicks because you will need a special tool to unscrew the fasteners. There is not much to gain from removing it so it’s best to just leave it alone.

Disassembly (Front Barrel):

The front barrel is rarely dismantled unless you need to get to iris or the aperture ring is not turning as smooth as you wanted. Oil from the helcoids can easily migrate here and cause a big problem just like what you will see here in this section.

IMG_9550The front barrel is composed of several mechanisms along with the objective. It’s easy to work on it so long as you don’t have to work on the iris. I will show you how to properly dismantle this thing so you won’t make any mistakes.

IMG_9552The aperture ring can be removed by loosening these 3 set screws. Be careful so you will not scar the screws’ slots or scar the surrounding knurling.

IMG_9553Like the focusing ring, the aperture ring can also be adusted. See all the oil underneath it and how it has evenly coated everything inside the lens? This is a sign that the lens spent a very long time in this state and the oil has migrated all over the lens. We just don’t see from the outside because the oil is wiped-clean through physical contact.

(Click to enlarge)

The collar that couples to the iris assembly is secured with this retention ring. There are 2 set screws that secure it, just loosen them and you can unscrew it.

IMG_9556Here it is. Everything was so oily so I left the ring soaking in an alcohol bath.

IMG_9557This pillar screw serves as a pin to couple the aperture collar/ring to the iris mechanism. Carefully remove this and make sure that you don’t snap it. These can be delicate and its head can snap if you’re not careful, these things are old and the metal can get corroded.

IMG_9558Here’s the pin and the aperture collar. Make sure that you don’t lose this little screw, you won’t find any replacement for these unless you salvage one from another lens.

IMG_9560This collar secures the objective so carefully remove it so you won’t drop the objective. It can be removed using a lens spanner, make sure that your hand doesn’t slip or the glass can get scratched!

IMG_9561It can take plenty fo turns to remove it but it shouldn’t be a problem. If yours is stuck use a bit of alcohol and pply it to the threads to soften what’s securing it before you attempt to remove it again.

IMG_9562This little set screw makes sure that the objective doesn’t turn as you change the aperture of your lens. It also helps secure the objective so you should also remove it.

IMG_9563The objective is now free to be removed.

IMG_9564Make sure that you don’t lose this shim washer. These are used to calibrate your lens so it can focus to infinity properly. These were made-to-fit at the factory and are unique to the lenses they came with so don’t damage or lose these.

That was easy wasn’t it? It’s only going to get harder from here so prepare yourself. For a lot of people whose only concern is to lubricate this lens then this is the furthest you will want to go. For problems that’s related to the objective such as dirty optics or an oily iris, the next section will show you how to clean it.

Disassembly (Objective):

The objective of this lens is tiny and working on it can make one nervous because it is so easy to damage it by using the wrong tools and not having the right skills and experience to tackle such a delicate task. Most of these lenses are in bad shape at this point and most show signs of an oily iris and the only way to address this is to overhaul it. I’ll show you how it’s done but don’t do it if you don’t have the right tools.

Cleaning the optics of this lens is easy enough but getting to the glass can be difficult due to the small parts used on it. You will need special tools to open them such as a pipe key, small lens spanners and other custom-made tools that only a decent repairman have. It’s important that you let somebody with the right tools work on this than damage this lens, they’re not cheap and there aren’t many around today.

IMG_9570The rear elements assembly can be removed using a lens spanner. It can be tight so use a bit of alcohol on the threads but be careful not to put too much because the rear element assembly has a cemented group and teh alcohol can hard the cement.

IMG_9571It comes of just like this. You can separate the optics from its housing but I don’t see why that should be done. It’s a very delicate procedure because it’s such a small part.

IMG_9572The front bezel can be removed by unscrewing it but you don’t have to do it because you can clean the glass without removing it. I just had to because of all the oil.

IMG_9573The front elements assembly can be unscrewed just like this. It can be hard to remove, it is usually so tight that only a special rubber cup will be able to grip it so you can have all the friction that you need to torque it out. Use a pair of rubber gloves so you can grip the small housing of the objective to help make your grip tighter.

IMG_9574The front elements assembly can then be separated further by unscrewing its rear. Don’t disassemble the housing of the 2nd element, you won’t be able to do it without damaging it and there’s no point in doing it.

IMG_9578The front element is secured by a retainer ring. I carefully remove it using a special tool I made called a pipe key. It can be scary to remove it because it’s so small and a slip will be enough to turn this lens into a total junk.

IMG_9579The front element can then be extracted. Be careful that you put it back properly because it can be hard to see its curvature since its rather flat and ambiguous to the touch.

IMG_9575The iris mechanism is being secured by this screw. Carefully remove it so you can get the rotator cup off to remove the iris leaves. This is how it should look like if the iris is open.

IMG_9576This is the rotator cup that secures the iris. Make sure that you put it back proprerly, the cup has a hole for the screw and it should line-up perfectly or else your iris won’t open or close properly.

IMG_9577The iris leaves were so oily that the whole iris came-off in one piece!

IMG_9580Each iris leaf was cleaned properly using naphtha and wiped-clean using lens tissue. The pegs at each end were punched and they can get detached if you’re not careful. They look big in this picture but they’re really tiny (and delicate) in real-life.

That’s it for the objective. This is its most complicated part and don’t dismantle the iris if you don’t have to. If it’s just a little bit oily then you can remove the optics and then dunk the whole assembly in naphtha and let it pickle for some time and flush-away the grime with a bulb blower and pray that it will be enough. This method is not acceptable if oil is present everywhere and has coated everything. A repairman should clean it thoroughly and that’s the only thing to do. An oily iris is seldom just that, it can sometimes trap dirt and a thin layer of rust can also form so those had to be cleaned properly. The lazy way I just outlined is only reserved for the inexperienced and is not the proper way to fix this.


The lens was easy to dismantle but it took a long time to put-back because the iris is tiny and too delicate for my clumsy fingers to repair and it took me numerous tries until the iris was re-assembled. I hadn’t repaired anything for months and the lack of practice was a big factor for wasting so much time on the iris. Overall, it took me about a night to fix it and most of the time was spent cleaning it and putting the iris back together. I also fixed the posts on the lens as they were wobbly. They can easily be lost if you’re not careful so I will advise you to secure it with lacquer or apply a bit of solder on the other side to make sure that it won’t loosen itself. The soldering part is a delicate job and only reserved for a master repairman with the right experience or else it will impede the lens when you fix it to your camera. I will not show you how to do it here because I didn’t do it for this lens.

The engraved numbers had to be restored so I painted them to make them look nice and to help me see them easier. I did it using the method that I described in this article. If you got this far in repairing a lens then why not just go all-out? That’s my reasoning because I am not just a collector but I also use the equipment that I repair. I also want them to last longer so I can use them longer and maybe my children can inherit them once I’m gone.

IMG_9581It took me several tries before I got them back! The trick is to put them back together and don’t worry about the pegs too much. I then use a very small pick that I fashioned from a small needle that I bent to shape to pick the pegs from underneath to put them into their respective holes. The leaves were secured using a small rubber cup so they won’t shift. If you are not familiar with working with these, read my post on repairing preset-type irises to help guide you through the whole process.

IMG_9631To adjust the focus of your lens so it can focus all-the-way to infinity, assemble the lens so you can use it with a camera. I usually use a digital camera for calibrating a lens’ focus so it’s accurate but I won’t do it this time because most mirrorless adapters are not accurate and I can’t trust them because of that. What I do is I mount any lens that’s not F-mount to a camera with the same mount (L39 in this case) and calibrate the focus with it. To know how I do it, read my article on how to calibrate your lens using the film plane. Now, to do that with this lens you must first set it to infinity and make sure that the lock is engaged and the post is touching the lock like what you see on the picture. You then turn the lens using its front barrel and check and see if it’s focused properly to infinity. You do that by focusing on something really far and make sure that the image you get is sharp. Once the resulting image is sharp, tighten the screws of the focusing ring to make it permanent. If you’re a keen observer then I’m sure that you now know how to adjust the aperture ring after reading this. It’s basically the same except that you check it with the opening of the iris instead of the resulting image at the film plane.

IMG_9633I love this lens a lot. I use it with my Nicca 3S a lot. It’s such a lovely lens now that it was overhauled and cleaned thoroughly. Couple this setup with the Voigtländer VC Meter and it’s now complete. The feeling of rebuilding a junk lens back to working condition is hard to explain and the sense of accomplishment that you get is priceless!

That’s all for this article. I know that my rangefinder-related articles aren’t popular but I have to write them because not a lot of people will do it. This article fills a big hole in the “internet knowledge database” so I hope that people will appreciate this article of a rare lens that not many people talk about. Not only did we tackle about the images it produce but we also touched on the topic on how to overhaul it thoroughly. This is the only place where you can access this bit of information. Thank you very much for patronizing and following my blog, I will continue to write articles for this blog as long as I have topics to write and the money to use to purchase equipment to repair. I am tightening my purse in the past couple of months and I will continue to do so in the coming years but I still have a lot of information in my notes to keep me busy for a couple of years to come. Thanks to you again and see you in the next article, 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.

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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.


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