Repair: PC-Nikkor 35mm f/3.5

Wow, it’s now September and it’s still HOT in Tokyo! Autumn is just around the corner and next month should be a lot cooler. I cannot wait to take pictures of the Autumn scenery in Tokyo because this is the most photogenic time of the year in my opinion. The boring concrete buildings will be accented with the vivid colours of Autumn and what better lens to take pictures that juxtaposition than this lens that I will be showing you on this post!

Introduction:

Ladies and gentlemen, may I introduce to you the PC-Nikkor 35mm f/3.5 lens! This lens is both unusual and historically important. I say unusual because this lens is a specialist lens that was specifically designed for architectural photography. This amazing Nikkor was also ground-breaking back in the days because it is the first lens for the 35mm format that can give you any control over the perspective of your image by modifying the vanishing point of your frame and hence – “PC” (Perspective Control) and not the destructive concept that is destroying our societies because it was taken too far and used out of context! Fuck PC!

IMG_0206Oh, such a lovely lens. This thing is heavy so do not let it’s small size fool you! It is a gem of a lens that was made with precision in mind. The lens is dirty in this picture but you are going to see it cleaned before your very eyes!

The next series of pictures will show you the lens in action. The left picture is the lens with no shift so we have a natural perspective wherein the building tapers tot he top. The pic on the middle shows the lens shifted mid-way (5mm~) and we begin to see the vertical lines straighten up and start to become parallel to each other. The right picture shows the lens in full shift (11mm~) and we now get a forced perspective wherein the vertical lines of the building is almost parallel to each other.

(Click on the thumbnails to enlarge)

If you study the picture closely, you will notice that the vignetting gets worse as the lens is shifter further from it’s 0mm (no shift) point. This is natural because the front element is not big enough. The shifted pictures look unnatural because of the forced perspective but it looks pleasing especially for architecture because the building looks “dignified”. This is what many people try to achieve in post so that buildings look nice on brochures and ads, ensuring unit sales. If you zoom into the picture you can see some smearing but this is the usual for these types of lenses and remember that this lens was made in 1962 and it is the first of it’s kind, prompting other brands to copy and surpass it. Good job, Nikon!

IMG_1406Here it is on the Df. The lens is almost at full shift here. Turn that large silver knob to shift the lens and turn the lens itself to make the whole barrel rotate from the centre of the lens mount. This is useful for manipulating the perspective of your image. Example would be if you are shooting from a high place and the bottom of the buildings start to look narrow on the frame, you can just rotate the lens to reverse the effect so the bottom of the buildings will look not look as tapered. Another example is when shooting down a long corridor, the lines will start to converge strongly at the vanishing point and to counter this effect you’re going to rotate the lens at the quarter position just like on the picture above. This is very useful for advertising because it will not make the corridor look small or look like a scary tunnel leading to somewhere dangerous.

IMG_0250The lens is of the preset aperture type wherein you open and close the iris manually. This is necessary because the automatic diaphragm feature is impossible to implement because the lens’ objective can be moved, making it pointless. Nikon will solve that by using electronic aperture on the modern versions of the PC-Nikkors. The lens beside it in the picture is the rare Micro-Nikkor 5.5cm f/3.5 lens. It also had a preset aperture that you manually open and close. This lens extends to more than 2x it’s collapsed length and that made it necessary to omit the automatic diaphragm feature. Feels like a dinosaur? It is! Owning one is like having a slice of 35mm photography history! Not many system will let you enjoy such heritage.

You operate a preset aperture lens by turning the aperture ring to the desired f-stop so that you constrain the aperture stop-down ring’s rotation so that it will not rotate past the f-stop that you wanted. You stop the lens down manually before making an exposure or just leave it stopped down all the time. This will give you a dark viewfinder when you take a peek but it can’t be helped. This only affects the cameras that will let you view through the lens so rangefinders have no problems with this since you are viewing from another mechanism.

IMG_0783The PC-Nikkor 35mm f/3.5 on full shift(11mm~). The lens was overhauled in this picture, it was bought as a junk for a relatively reasonable price. Not cheap but reasonable.

It is also worth mentioning that this lens will NOT mount properly on later Nikon cameras (film or digital) that doesn’t have a collapsible aperture coupling tab. Keep this in mind so you will not damage you cameras by trying to mount this thing to it. The Nikon Df and the Nikon F4 has collapsible aperture coupling tabs that neatly gets out of the way so that you can safely mount this lens on them. Another thing is that the big chrome knob will hit the prism of some Nikon cameras when shifted and rotated in a particular position and this is affecting older or newer cameras with long overhanging prisms.

OK, that’s it for the intro. I am not running a review and Nikon history blog so let’s move on the teardown!

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 (Separating the Front Part):

This lens is unusual so we have to go back and forth a bit but we always need to separate it into smaller assemblies to make things more manageable as well as protect the objective by separating it and storing it somewhere safe while we work on a different assembly.

IMG_0207We start by removing a ring that holds the front assembly of the lens to the main barrel. It is a common way for most preset-aperture Nikkors to have their objective/front assembly secured this way – the Micro-Nikkor 5.5cm f/3.5 is another example.

IMG_0208The ring can be removed easily with a compass. The ring is situated too deep to be accessed by the lens spanner unless you milled special bits for it. My lens spanner has longer bits so I can access rings that are 3cm deep. I milled them from the shaft of an old screwdriver.

IMG_0209The front part should come off easily now that the ring is gone. It is heavy so take care not to drop it to the floor!

Disassembly (Shift Mechanism):

The main barrel comprise of the shift mechanism and the focusing unit (helicoids). I will divide this into 2 parts so it is going to be easy to follow and explain.

IMG_0210Make sure that the lens is set to it’s rest pose by focusing it to infinity and also turning the barrel so that the number 8 on the chrome ring is centred.

IMG_0211Now, on to the rear! Remove these 5 screws to get rid of the bayonet mount. If these do not move a bit, put plenty of acetone or alcohol and wait for a couple of hours before you give it another shot. There is not point in brute-forcing these things because replacements are not easy to find.

IMG_0212The bayonet mount should come off easily since there is nothing that is connected to it…

IMG_0213Now, we need to remove these 3 smaller screws to free up the rotating chrome collar.

IMG_0214The chrome collar/grip is connected to this brass ring, which we will leave for now because we are going to get rid of some other things to make things easier to grip.

IMG_0215The focusing ring can be removed by removing these 3 screws.

IMG_0216The focusing ring on my lens came off easily since it wasn’t glued into place.

IMG_0217Next, we need to remove the shift knob. Unscrew these 2 screws…

IMG_0219Twist the knob until it comes off. During reassembly, simply screw the knob back into the hole until it sinks in completely. Do this while the lens is not shifted.

IMG_0220Now that the know is out of the way, we can now grip the lens barrel better without having to think about anything that would accidentally get caught and break.

Remove this set screw to free up the retention collar that houses the rotation mechanism.

IMG_0221Use a lens spanner and carefully unscrew the retention collar.

IMG_0222That big piece of brass comes off with the collar. You can separate these later and overhaul these separately to remove the gunk and corrosion that it accumulated through the years.

IMG_0223This mechanism with the small metal ball is what is responsible for the clicking action of the lens rotation mechanism as well as keeping it tight. If you want the clicking action to be tighter, simply adjust and bend the leaf spring under it. Removing these 2 screws will give you access to the spring. Be careful not to lose the ball because nothing is holding it in place.

IMG_0224To dismantle the shift rail/guide mechanism, simple unscrew these 2. Be careful with the 2 because mine was glued tight so yours maybe as well. Use copious amounts of solvents to soften the glue up before attempting to unscrew these.

IMG_0225With the screws gone, you can now remove one part of the “clamp” for the dovetail.

IMG_0226The other one should come off rather easily but be careful because there is a screw that is used as a guide and it fits into a slot so you may have to play with it a bit before you can get it out safely.

Disassembly (Helicoid):

Now that we got the shift mechanism out of the way, we can now work on the helicoids!

IMG_0227Begin by removing this pillar screw. You may need a bigger screwdriver for this, just look at that slot. Be careful not to use the driver at an angle and ruin the thread.

IMG_0228Once the helicoid key is gone, you can now separate the central helicoid from the outer one but please mark where they separate. Forgetting to do this will result in hours of stress so you want to avoid all the guesswork of finding where this thing should mate by marking it down in this step.

IMG_0229The inner and central helicoids look simple enough. See that scratch that I made? That is for me to know which side should face the infinity mark.

IMG_0230Separate the remaining helicoids and again, don’t forget to mark where they separate!

Disassembly (Front Assembly / Objective):

I would usually discuss the objective and the other parts’ disassembly separately but not for this lens because they are inter-connected so please pay attention.

IMG_0231Do not lose this brass spacer. This little spacer is used so that the lens can be calibrated for infinity focusing easier and I believe that this part is unique to the lens that it came from. I am sure that Nikon has boxes of these with the same diameter but of different thickness so that the people assembling this thing can get the right one to use on the lens that they are currently assembling.

IMG_0232To remove the aperture stop-down ring, simply unscrew these 3 flat head screws. You rotate this ring to manually open and close the iris because this is a preset aperture lens.

IMG_0233Be sure to mark which hole goes where!

IMG_0235Before we go any further with this, the front optical group should be removed from the rest of the front assembly and keep this thing somewhere safe while you work on the rest of the lens.

IMG_0236The same should also be done for the rear element. I unscrewed mine using my bare hands and if yours was glued then you should drop some solvent into the thread before you give it another try.

IMG_0237With all that delicate glass safely out of the way, we can now continue with the mechanism that controls the iris. Unscrew these to free up this ring.

IMG_0238This ring was connected to the aperture stop-down ring and rotating this thing will close or open up the iris manually.

IMG_0239Carefully unscrew this ring from the rest of the lens and make sure that you don’t damage those delicate threads! Cross-threading this part will render that your lens useless since you cannot open or close your iris properly.

IMG_0234This is the aperture ring. Unlike most lenses for the F-mount, preset aperture lenses usually have their aperture rings in front of the lens like rangefinder lenses do. Remove these small screws to detach it from the rest of the lens.

IMG_0240You will that the aperture ring will not go anywhere and that is because the aperture stop is in the way. This part ensures that this ring is restricted to a couple of degrees so it will not make a full turn. Simply unscrew these 2 screws to get rid of the stop.

IMG_0241And off it goes! Just look at the amount of dirt and grime on this thing.

IMG_0242The stop (from 2 steps back) is coupled to this guide ring. This guide ring is also responsible for keeping the pressure plate/spring in place. Removing this ring is easy, just unscrew the small screws that hold this thing in place. Notice that the notch on this guide ring begins at the maximum aperture (f/3.5) and terminates at the minimum aperture number found on the beautiful chrome tip of this lens. Now you see how this ring restricts the motion of the aperture ring.

IMG_0243Be careful not to damage anything while removing that ring.

IMG_0244This ring holds down the pressure plate for the aperture detent mechanism.

IMG_0245It can be tight so be patient while removing this thing. The aperture detent ring is the silver ring with slots milled into the inner surface. These slots correspond to the numbers in the lens’ chrome tip and tiny screw goes in and out of the slot each time you pull and turn the aperture ring and that gives you the clicking action so that you know precisely which f-stop you are currently at.

Disassembly (Iris Mechanism):

The iris assembly of this lens is pretty simple but can be a bit frustrating because it is the same type used in a lot of rangefinder lenses in which the individual blades are shaped like a “V” instead of the usual curved blades that we see in SLR lenses. These blades interlock with each other and it can be very annoying to put them back together. These things can at times be oiled by a technician, making the iris damped/smooth. I do not adhere to this oil on the blades practice because the lubricant can go bad and gum-up when it collects dirt. I will clean these blades whenever I find them just in case. This ensures that the lens will be oil-free for more years to come.

I will also mention the obvious; in case you haven’t noticed, the housing for the iris is very prone to being fouled by the lubricants used for the aperture ring and aperture stop-down ring because of the proximity as well as the direct linkage. The lubricant can migrate to the blades if you applied too much of it so be careful and lubricate it just enough so that it isn’t coarse or too oily. This takes some experience to determine at times and I will share to you how I do it. I would simply rub the threads on the ring and the housing with the very same brush that I use to apply my grease but this time I would just brush it without dipping the brush in the grease pot. Essentially, I am just using the residual grease left in the brush. If you think that this is not enough then you can lightly brush the inside wall of the pot so it will only collect a thin film of grease. Remember this – it is better to err on the side of not having enough grease that applying too much of it.

IMG_0249To open up the iris assembly you should remove this copper ring. Be sure that there are no screws attached to the inner basket / rotation plate or else that screw will prevent you from removing this part.

IMG_0248The rotation plate / inner basket is responsible for keeping the blades together. Never apply any lubricant to this part. I would clean these parts thoroughly with a clean tissue soaked in lighter fluid or alcohol. Be sure not to leave any lint or fibres by blowing these with your rocket blower because any dirt that you leave here will end up in the glass.

IMG_0247And here are the blades! There are 2 pins in each blade, one of the pins should be inserted into it’s corresponding hole at the floor of the housing and the other pin goes to the slot in the rotation plate. I advise that you take plenty of pictures before you dismantle this and study how this mechanism works to get a full understanding/appreciation of it. I have also fixed dozens of Nikkors but I will never let go of this habit. I would even go as far as claim that I fix these things just because I wanted to see and understand the engineering behind these things.

Clean these blades by wiping them with a clean lens tissue saturated with alcohol or some lighter fluid. There are times that these will get rusty and cleaning them will prevent them from corroding any further (at least in a couple of years). Be careful not to bend or damage these things because a warped blade will prevent the whole iris assembly from functioning properly.

Disassembly (Objective):

The objective is pretty straightforward if you have any experience with these things. Make sure that you have the proper tools before attempting to work on these things!

IMG_0264The rear optical group can be opened by unscrewing this ring with your barehands. If this will not budge then apply a small drop of solvent to the thread to soften the glue. The rear element might drop to the floor so be careful!

IMG_0265 2The front group houses the rest of the glass. Unscrewing this part will give you access to the glass element in the rear of the housing and again, do not drop anything.

IMG_0266The 2nd element group is a heavy piece of doublet glass. A doublet is basically two separate glass elements that were cemented together to form a single unit. Do not apply too much solvent or alcohol on this part or risk ruining the cement used on this thing.

IMG_0282The front element of this lens can be accessed by removing this retention ring. Use a lens spanner to open this thing up and be careful not to scratch anything. Again, if this part is glued then you should do the alcohol routine again on this part.

IMG_0283Wow, just look at that thing. The front elements need to be this big despite it’s relatively slow maximum aperture to accommodate the changing geometry of the lens. Mechanical vignetting affects this lens when it’s shifted towards the far end of the scale. Mechanical vignetting simply means that something is getting in the way of the optics’ view. Example of which is taller filter rings in really wide lenses –  you get dark corners.

Conclusion:

Wow, that was complicated don’t you think? Overhauling this thing will keep you busy the whole day and will be a fun but worthy challenge to experienced technicians. I had plenty of fun with this thing and learning lots of things along the way,too.

IMG_0246Cleaning everything thoroughly is a must! If you didn’t then you have just wasted hours of your life. Clean the hole for the knob by inserting a rolled lens tissue. It took me plenty of tries before I was satisfied enough with this hole. If you have a small pipe cleaner like the ones for baby bottles or nipples then use that, even those fancy dental floss that look like pipe cleaners can be handy for cleaning this. I use the heaviest grease available to me for this screw hole. This is the same grease that I use for tripods and the consistency is gloppy like molasses.

IMG_0218The inner surface of the knob for shifting is lined with a strip of felt or suede. Many of the PC-Nikkors on the market with loose knobs is caused by the liner getting worn/damaged. I removed the old liner and replaced it with fresh material to ensure that this lens will not slide when shifted. Even after using a 1mm+ liner made of suede on this knob, the lens will still slide a bit if shifted 80% of the way due to the heavy front of this lens. It will slide by a millimetre so it can be annoying but it is a lot better than how it was originally. Remember that this is Nikon’s first shift lens for the F-mount and it was quite the achievement.

IMG_0783The dovetail shift rail mechanism was also lubricated with the same thick grease so that it will be as damped as possible. I tried using a thinner grease but it just won’t do so I had to overhaul the shift mechanism twice just to replace the grease with the thickest one I have.

Before totally reassembling your lens, do not forget to calibrate the lens to focus to infinity because this lens was designed for architectural photography and nailing the infinity focus is essential. Go back to the focusing ring disassembly portion to study how this is done. I did not even bother calibrating mine since my lens focuses to infinity properly. Nikkors of this era are built to exacting tolerances so there is usually very little need to calibrate the lens for infinity focus.

IMG_1505.JPGWhat a little jewel, so compact but dense. It is not much bigger than the usual Nikkor lens. Forget about using this for street photography, it is pointless because of the dark view.

That’s all for this post. This one took me several nights to write so I hope that you enjoyed this. This is the only resource on the internet that tackled the complete disassembly of one of the more unusual Nikkors in any collection. I will keep the standards of this blog as high as I can and the next lens will be another first – a teardown of a legendary Nikkor! The stuff of dreams and desire. 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 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.

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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6 Comments (+add yours?)

  1. Trackback: Internet Nikon Repair Resources – My Take on Photography and Diving (Underwater Photography Mostly)
  2. Mike D
    May 01, 2017 @ 05:55:54

    came across your blog while doing some search for my 24mm 3.5 pc, it is a bit loose, is it necessary to open the shift mechamis to tighten it? can I just add some thick grease to the rail externally? thanks, Rickard.

    Reply

    • richardhaw
      May 01, 2017 @ 09:27:32

      Hello, Mike.
      When you say loose, you mean it cannot hold itself when shifter? I do not know which lens you are talking about exactly but the older ones would need a felt lining under the dial/lock to prevent it from slipping. Ric.

      Reply

  3. Mike D
    May 01, 2017 @ 15:08:48

    thanks, Rich for the quick resposne, sorry, it is old 28mm 3.5 PC, yes, the lens cannot hold when shift to the maximum and slides due to its own weight, is that easy to open the dial/lock? I guess you mean the little knob right?

    Reply

    • richardhaw
      May 01, 2017 @ 16:01:00

      Hello, Mike.
      Yes, the silver dial/knob. You can slip a sheet of velvet or felt thin enough to fit under it. make sure it has glue for the final installation but try it without adhesives first. Ric.

      Reply

  4. Mike D
    May 01, 2017 @ 16:11:00

    perfect, thanks very much, will try and let you know

    Reply

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