Repair: W-Nikkor.C 2.8cm f/3.5

Hello, everybody! Today is the first day of 2018! I wish everybody a great and prosperous 2018 and I hope that all of the past year’s misfortunes will be rewarded with prosperity this year and everything will be balanced out perfectly. Speaking of balance, we will talk about a good and balanced lens from a long time ago. It was a very important lens in the world of 35mm rangefinder photography. Stay and read the rest of the article to find out.

Introduction:

The W-Nikkor.C 2.8cm f/3.5 debuted in 1952 and was considered to be the fastest lens of its class when it came out. At a time when wide-angle lenses for the 135mm film format were as slow as f/6.3 or less, this lens surely made things more interesting. It was based on an old aerial photography lens made by Nikon for the Imperial Japanese military and it had low distortion and good resolving power. It was then miniaturized so end up with the W-Nikkor.C 2.8cm f/3.5 lens. This is a very compact lens and its simple 6-element lens construction is small and delicate. I’m sure that Nikon could have made this even faster but I don’t know what’s keeping them from doing it since there’s enough space in the lens barrel for a bigger objective, your guess is as good as mine.

IMG_4562The W-Nikkor.C 2.8cm f/3.5 is a very compact lens. If you think that this lens looks similar to the W-Nikkor.C 3.5cm f/3.5 then you’re guess is correct. This lens’ barrel was based on the W-Nikkor.C 3.5cm f/3.5 and handling is very similar between these 2 lens.

IMG_4566It’s very compact you can even store it in your pocket! Despite being tiny, it’s heavy and it certainly feels dense. This is because this lens used brass in its construction. There are no light alloys used on this lens and Nikon will only begin to integrate the said alloy a couple of years after this lens was introduced. You can seriously injure somebody with this!

IMG_7245The lens balances perfectly on the Nikon S2. You will need a separate viewfinder for this and any accessory viewfinder will do, even the ones made by Leica or Contax. If you own the Nikon SP then the edges of the wide-finder frame is equal to 28mm. I often mount this lens with the Nikon SP just because of that built-in wide-finder fro 28mm.

(Click to enlarge)

Wide-angle photography is generally dominated by pictures of architecture or nature. It’s natural to grab the widest lens you have and shoot these subjects. This lens is great since the distortion really isn’t very noticeable in my pictures. The vertical lines generally stay straight. I’m sure that you can find some distortion when you shoot a brick wall but don’t worry about it for practical photography. Just go out and enjoy shooting!

(Click to enlarge)

28mm may be too wide for some people for street photography but it’s certainly useable. In fact, some people prefer using it over 35mm! I’m OK with either focal lengths and I use the 28/50 combo when I go out shooting so this is perfectly fine with me. Shooting with a 28mm lens also means you have to get closer to your subject so be prepared! You can see that the old guy on the picture to the right isn’t in-focus. That is because my lens’ focus is not optimum and I will show you where and why this happened later in this article.

IMG_7244Let’s see how this lens performs on a high MP digital body. The Sony A7 is the only digital full-frame mirrorless body that I have so let’s see how it performs with it.

DSC00822Compared to modern lenses, this lens shows its age when you zoom-in and pixel-peep. Its resolving power is barely able to cope with the Sony A7’s 24MP sensor but if you are not into these kinds of things then using this lens on high MP digital cameras for real-world photography is more than fine. I am liking the lens so far despite its quirky and outdated handling and it matches the poor ergonomics of the Sony. OK, I’m being too harsh on the lens to compare it to the Sony. Yes, Sony cameras have terrible handling and ergonomics.

DSC00858.jpgThis picture should show you that there aren’t any noticeable distortion from this lens. It is very impressive considering that this lens is almost 70 years old! The one things that is really bothering me is the vignetting. There’s a lot of it wide-open and it doesn’t seem to go away even if you stop it down (but it does go away to some extent).

(Click to enlarge)

These pictures should show you how beautiful this lens is when used for its intended use like architectural photography. The vignetting doesn’t really show up in real use and the straight lines all remain straight. Color rendition is on the cool side, very typical of older lenses because these were corrected for use on monochrome film.

(Click to enlarge)

Here’s the real weakness of the lens. Flare and ghosting are both terrible with this lens. Despite the big red “C” designation in its name, the coating is inadequate by today’s lens standards. Stopping it down only solidifies the ghosts and help alleviate the flaring a bit. If you want an exotic lens for the flare and ghosts then this lens is for you!

(Click to enlarge)

Here are a series of pictures shot from f/3.5, f/5.6 and f/8 respectively. Wide-open, the lens is already showing a strong center. It’s sharp and stopping it down doesn’t really make it any much sharper. Vignetting however, is almost ever-present. Never mind the thing on the lower-right corner, that’s just my finger covering the frame!

That’s it for the introduction. As you can see, the lens is very nice for practical use and its flaws are compensated by the sharp center and excellent distortion control. One thing is lacking but that has more to do with the limitations of the rangefinder system than the fault of the lens’ design and that’s the inability to focus really close. For a wide-angle lens, the ability to focus close is what makes or breaks the lens. Even if you use adapters with it, the built-in focusing unit simply won’t let you do this. I guess thing can’t be helped in this case and we should just accept it as it is. Besides, this is a rangefinder lens anyway.

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 now-growing 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.

Lens Barrel:

This is an easy lens to work with so long as you have the proper tools. You’ll need to use screwdrivers that fit properly to prevent stripping the heads of the screws and be careful not to scratch the beautiful chrome finish because it’s such a very prominent feature of this lens. Maintaining the beautiful finish is important to restoring these shiny lenses.

IMG_4563Just like any wide Nikkor from this era, this lens is being held-together by this collar at. It serves as its crucible and removing it will separate the lens into its 2 main components.

IMG_4564Here’s how it should look like once you removed the collar. Now that you have seen this, make sure not to drop anything to the floor while removing the collar. The objective is a heavy assembly and it can free-fall to the floor if you’re not careful. Also make sure not to misplace or damage that shim because it’s used to help calibrate the lens so that it can focus all the way to infinity and is pretty much unique to every lens.

Store the objective in a safe place and make sure that it doesn’t roll-off from the edge of a table or workbench. I would store it in a film canister filled with tissue if I were you.

IMG_4567To remove the rangefinder coupling cam, you will need to unscrew this big screw. Make sure that you don’t damage it while you remove it. The spring should also sit properly on top of the screw when you put everything back together.

IMG_4568The cam can now be safely removed once the screw is gone. The screw is the only thing that’s keeping it all together. This cam couples to the rangefinder inside the camera so it can mechanically convey information from the lens to the rangefinder, enabling the lens to help move the rangefinder so that the little rangefinder patch moves left or right.

IMG_4565Before you can separate the helicoids, you must remove this screw. This can be delicate, I would use caution when removing this because if you bent or broker yours in two then it is going to be a big problem to get this out. The metal used on this thing can get brittle so it may break or get stripped easily. I think this was made from brass. The screw acts as a stop of some kind so that the helicoid will remain within its rotation range.

IMG_4566Now that the screw is gone, you can now rotate the focusing ring past its focusing range. This is how much it can go when you retract the lens. When I put the lens back, I should get the same result. If I got a different orientation then I screwed up the helicoids’ mating position and they meshed in the wrong position.

IMG_4569Now that the screw is out of the way, you can now unscrew the helicoids but make sure to remember where your helicoids separated. Mine separated roughly on this point. The helicoids should mate where they separated and if you got it wrong then you won’t get it back together properly. Read my article on working with helicoids if you’re new to this.

IMG_4570Finally, the aperture ring (or cup in this case) can now be unscrewed.

IMG_7248This is the detent spring. It catches on the notches on the inner side of the aperture ring so you get a reassuring click whenever you change your aperture.

IMG_7247The focusing ring can be easily removed by unscrewing the 3 grub screws around it. It is not essential to remove it but if you really have to then this is how you can do it. Look at the picture and see that the screw holes on the focusing ring corresponds to the dimples on the wall of lip of the helicoid. Make sure that you line these up properly or else your grub screws won’t sink-in properly.

Nikon’s rangefinder lenses are easy to work with compared to F-mount lenses. They have far less parts and the assembly is usually straight-forward. This lens is no exception and its construction is conventional in every way.

One very important word about choosing which grease to use on this lens. Make sure to use the lightest grease available to you when you lubricate the helicoids. This is because there are 2 sets of helicoids that you must turn in order for this lens to focus, one at the camera and the one that’s built-in to this lens. If you used a heavier grease then that will just add to whatever friction you’re getting from the camera’s helicoids and things’ll add up and you end with a stiffer than ideal feeling when you turn your focusing ring and it’s also going to be wear-out the gears of your focusing wheel each time you turn it because the added resistance will ear the brass teeth easier. I hope that you follow me on this.

Objective:

The objective is of conventional construction but it was made very solid in every way. It’s a very good example of how things were built in those days before companies would use “planned obsolescence” to force the consumers to upgrade and part with our money. This is easy to work with and it will take you only a couple of minutes to pull it off so long as you have the proper tools to do this. Having the right tools is key to a successful repair.

IMG_4571The front elements assembly can be easily removed by unscrewing it with your hands. It has an exposed back to be careful not to chip it or your lens is going to be a pricey junk.

The front element can be accessed by removing the front bezel with a lens spanner or a small rubber stopper. Be careful not to drop the tiny front element to the floor!

IMG_4572You can then open it up further by unscrewing this collar. The lens elements are tiny and delicate so special care has to be given in handling these things.

IMG_4573You can remove the rear lens assembly with a rubber stopper or with a pair of specially-modified tweezers. Don’t force your way or else you may damage the rear element.

IMG_4574The inner element assembly can be removed by using a lens spanner. The slots are clues as to what tools you need to open this thing up.

IMG_4575It’s made of solid brass and you rarely see something this well-made these days.

This should be an easy task for you. The parts are so small and delicate, I sometimes used a Q-tip to access some of the parts. It only took me a couple of minutes to clean this and it was a joy compared to some of the other more difficult lens designs that I had seen.

Iris Mechanism:

The iris mechanism is pretty conventional. It’s similar to many lenses from this era. This is not difficult to understand in terms of how it operates. The whole thing was made with thick-gauged brass and the overall feeling that you get is that of a well-made product.

IMG_4579This is how solid the housing for the objective is. Do not bother to remove the set screws here because they are used to regulate the size of your iris. I would just leave that be if I were you. It’s a precise adjustment made at the factory and is best left as-is.

IMG_4576The iris mechanism is being held together by the brass retainer. You can carefully get rid of it by using a small screwdriver to carefully pick it out. Look at how dirty the iris was.

IMG_4577Finally got it off. Make sure that you don’t damage the iris while removing this.

IMG_4578The rotator cup for the iris is being held by this screw. Carefully remove this because like the other screw we removed in a few steps before, this thing can be delicate due to age.

IMG_4580Here’s the rotator cup. Carefully remove it with your fingertip or a pair of tweezers.

IMG_4581Here’s the iris. You can drop it to your palm if you wish. Whatever you do, be careful not to damage or warp the individual leaves.

IMG_4582Soaking the parts of the iris assembly in benzine will dissolve any oil in it.

IMG_4583Carefully wipe each individual iris leaf with a soft lintless tissue. Never let them air-dry or the solvent will leave drying marks on its surface.

IMG_4584Despite its tiny size, the iris was not difficult to put back. Read my article on how to work with preset-type irises to know more about how to put these things back together.

That’s all for the iris assembly. It can be difficult to work with something as small as this but it certainly isn’t impossible specially if you’re used to it. Some people would just soak the whole iris assembly in a can of chemicals, hoping that it will clean everything. That is not the proper way to do things and there is no substitute to cleaning an iris assembly.

Conclusion:

This was an enjoyable lens to work with and despite its conventional schematic I learned plenty of things just by working on this. I hope that you guys learned something here and I hope that this article reaches somebody who would want to open theirs but don’t have a clue on how to work on it. If you have no experience working on lenses then please do yourselves a favor and just send this to a qualified repairman and show them my blog. It is going to be cheaper for you that way because buying the proper tools will cost money. If you screwed up your repair attempt due to inexperience then this will end up costing you more. This blog was originally made to inform people on how a lens is repaired and also to help people determine if a repairman did a good job or not so I hope that this blog has fulfilled its purpose in that regard (apart from entertaining you).

Before I can put everything back together, I will have to do somethings first. Because this lens was made almost 70 years ago, the old lettering isn’t as nice as it used to so it had to be worked on just to make it look acceptable. I’m not a collector so I don’t mind this at all. Collectors will not want this because they want the lens to be as close to original as much as possible. I would consider myself to be a user-collector. I collect knowledge and pass it on to my readers!

IMG_4585The lettering was touched-up by using some enamel paints. My article on how to restore the lettering on old lenses will be helpful in case you are not familiar with this process.

I also had to fabricate a new shim to add to the existing one. It is just 0.2mm tall and this is how delicate adjusting the focus can be. Some idiot may have lost one of the shims or a dummy at the Nikon plant may have approved this so it passed quality control but this is not acceptable to me. That 0.2mm difference is causing my lens to mis-focus and instead of having infinity at the end of the focus range, I have my infinity set to around 15ft! This is probably the reason why I am getting some blurred shots on film! I am pretty good at guessing distance with a focusing scale but if your focusing scale is correct but your lens isn’t seated properly then we have a problem. The new shim was made from a length of stainless steel vaping wire. I needed 0.2mm so I had to sand it down by hand to get that.

This is a trick that I use when I encounter things like this. It’s very rare that I have to do this but this is how you can solve this kind of problem. Fabricating parts is part of every repair and maintenance hobby and this is no exception. Back in my grandfather’s watch repair workshop, our watch repairmen had to fabricate their own parts when they can’t find any matching spare part in the junk drawer.

We have reached the end of another blog post. I hope that you enjoyed this one because I have put a lot of effort into this. I hope that this sets the tone for all my posts this in 2018! I strive to give you the best that I can and I hope that you will continue to follow my blog. If you enjoyed this post, please share this on social media, this will help our community grow bigger and we can reach more and more people who wish to get entertained while getting informed on camera and lens repair. For those of you who have met me in person you all know that I love to crack jokes and I really hope that my style of writing has given the camera repair world a new style. Thank you guys again and see you on the next blog post! I have a week’s vacation so I have more time to write! Happy 2018, 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 paypal.com account (richardHaw888@gmail.com). 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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Thank you very much for your continued support!

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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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4 Comments (+add yours?)

  1. The Count Gustaf
    Jan 02, 2018 @ 04:58:54

    wow, thanks a bunch. Beautiful pictures

    Reply

  2. Trackback: Repair: Infinity Calibration Tools (pt1) | Richard Haw's Nikon Maintenance Site
  3. Trackback: Repair: W-Nikkor・C 3.5cm f/2.5 | Richard Haw's Nikon Maintenance Site

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