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Repair: Noct-Nikkor 58mm f/1.2 Ai-S

How are you, readers? I have not updated my blog for weeks and I can see that people are checking my site on the weekends looking for updates. The past few weeks were terrible. I got sick and the rest of the family got ill as well including our precious baby. I am so busy at work and having an idiot as a team mate doesn’t make things easier so I am left with no time to update this blog and stress levels are very high. Don’t worry, I will make it up to you because we are going to teardown a very special lens this time.

Introduction:

We are going to feature a legend in this blog post. A lens so steeped in hearsay and fantasy that it’s reputation preceded it. The fact that this lens is rare and out of production is also contributing to the hype. And as a Nikon tinkerbug, this lens ranks very high on my list. It is like hunting down and killing Moby Dick and this lens is no other than the now-legendary Noct-Nikkor 58mm f/1.2 Ai-S!

img_1658This lens when coupled with a camera that has a Nikon D4 sensor will enable you to shoot in really dim situations like a candle-lit room with ease. The Noct is designed to be used in the dark or night photography. One of it’s selling points is how it corrects points of light found on the corners of the frame. Usually, large aperture lenses will distort these points of light when shot wide-open but the Noct is corrected to help keep the shape of the lights and prevent these from smearing. It’s not perfect, but it is much better than many lenses for this.

This lens has a long but low production run. It started with an Ai version and ended being an Ai-S lens that was produced until the mid ’90s. The differences between the earlier one and the last version are the coatings, aperture blade number, weight, different lens barrels and other small details, the formula stayed the same as far as I know. The yield was low for this lens because the front element had to be ground by hand. Scarcity and hype made this lens expensive to purchase so I waited for a very long time until I could buy one for a good enough price, I got it for around 60% of the running price here in Japan.

Another selling point of the Noct is it’s sharp wide-open at f/1.2. It may not be the best at minimum focus distances wide-open but from 2-3m and further, this lens is sharp at f/1.2 and it will not disappoint. Couple this with the lovely bokeh that this lens is known for and you get an image with plenty of character and looks unique in most cases, specially when shot at night. Some would even go as far and say that no other lens is designed to do this and as high as that claim is, I am sure that it is not made without basis.

But 58mm, why 58mm? The optics is so large and it is verging on the limits of the F-mount and a shorter focal length with these features cannot be achieved so a compromise had to be made. Engineers reused solution for the Nikkor-S 5.8cm f/1.4 lens – the first normal f/1.4 lens for the F-mount. It is a historical lens for Nikon because achieving a fast aperture on a normal focal length was difficult then so instead of 5cm (50mm), the engineers made the decision to design it as a 5.8cm (58mm) to get proper clearances. This rare Nikkor sold for a short time until the Nikkor-S 50mm f/1.4 lens was made possible by advances made in the field of lens design. I also got some information that 58mm is the closest focal length that coincides with the human eye and can be tested by shooting a 58mm lens and comparing it to what your eye can see (left or right if you still have both). I haven’t tried this one myself so please feel free to test it for us and tell us over here what your findings are.

Check out my ugly sample images and judge them for yourself specially the ones where I was focusing on something close to see what I mean when I said that the lens is not really very sharp wide-open on minimum focus distances. It is possible that I got a lemon where the minimum focusing is screwed. My Nikkor 50mm f/1.2 Ai-S was the same and since I bought it new, I pestered Nikon to fix it to my satisfaction and after 2 months of bugging them they finally gave me a perfect lens that is sharp at ALL distances and at every practical aperture. Some people actually have a sharp copy at the minimum focusing distance and they even use it as a macro lens of some sort when mated to an extension ring.

In terms of sharpness, I would rank this lens in between my Nikkor 50mm f/1.2 Ai-S and the Nikkor 55mm f/1.2 Ai, which is saying a lot because these lenses that I own are pretty sharp wide-open. You can even say that it has the dreaminess of the Nikkor 55mm f/1.2 Ai and the sharpness of the Nikkor 50mm f/1.2 Ai-S in most cases.

img_1631Wow, just look at that sexy front element! That is an aspherical lens element and it has to be hand-ground for precision, this is the reason why  this thing costs so much to build and rejects are also high since there is a man involved in the production of this thing. You can even see my coat hanger with my drill stand, leather jacket and camera bags on the other side of the room opposite me!

Is this lens worth the money? That is a very hard question to answer. To some, the unique rendition that this lens gives you is worth that. For people on a budget, I will tell you now that the Nikkor 50mm f/1.2 Ai-S is going to give you what you asking for. The older and less sharp Nikkor 55mm f/1.2 Ai series of lenses are also great substitutes most of the time but I can tell you that they are no Noct-Nikkors when shot at night or dimly-lit places. Just look at the gorgeous transition of the bokeh!

If you want to know more about this lens then you can just search for reviews of this lens in the net because we are now going to begin with 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 (Lens Barrel):

I usually separate my disassembly into 2-3 parts but this lens is simple enough so I am just going to cram everything into 1 part. Do not lightly take the fact that I mentioned the word “simple” for this lens – it is anything but as you will soon see.

This lens is best opened from the front like most typical Nikkor primes. Everything else is typical and not noteworthy until you reach the helicoids but do not worry because I will be showing you the ins and outs of this lens (literally).

You do not need any special tools if you want to service the helicoids but you will want to be careful with your screwdriver. This is a very valuable lens by all accounts and it is not in production anymore so treat this lens like it belongs to a god who can zap you just for fun. I kiss this lens from time-to-time and I am not joking.

img_1632Begin by removing the set screw found on the front barrel. Be careful not to damage these. Mine was sealed with black paint, others may have their’s sealed with a clear varnish. Just drop a bit of lighter fluid to soften the paint and work on the screw slowly.

img_1633Simply unscrew the front barrel and it should come off easily. The front barrel is the only thing that holds the objective so do this while the lens is facing up or else you will drop the precious (and heavy) glass that makes this lens so expensive!

img_1634Just look at the size of that thing. I can tell you now that this is very dense and heavy. It is very scary just holding this thing for the picture! The objective can be pulled out from the focusing unit just like this.

img_1635Wow, Nikon really put a lot of effort into engineering this little thing. So many things were cramped into this tiny space just to make it compact. I will show you the innovations made in the next couple of pictures. This was one of the reasons why a modern autofocus version was never made. Lenses back then were designed around the objective while most modern lenses have to be designed with autofocus as part of the scheme.

img_1636Now that the objective is gone and safely stored we can now continue with the dismantling of the focusing unit / lens barrel. Remove these 3 screws to get rid of the bayonet. The older Ai version of this lens has 5 screws on the bayonet mount and I feel that for a lens this big, heavy and prestigious such cost-cutting should not have been implemented.

img_1637The rear bayonet plate can now be safely removed and cleaned. Resist the itch to remove the aperture ring at this moment and wait for the next few steps.

img_1638The aperture ring won’t come off because these 2 screws connect it to the aperture fork on the other side. Just unscrew these 2 and be careful not to scar anything with your tools.

img_1639And here is the aperture fork. The slot in the middle mates with a lug / pillar screw found on the side of the objective and it is responsible for opening and closing the iris.

img_1640The aperture ring came off rather easily after the fork and screws are out of the way. There is nothing note worthy here.

img_1641Remove these screws so that you can separate the chrome grip from the rest of the barrel. I was really careful with this step as I do not want to risk skipping and ruining anything on the grip, if I scarred the beautiful knurling then this lens will get ugly. Remember, this is not a cheap lens.

img_1642The chrome grip wasn’t glued in place at all. I was expecting that Nikon may have glued it in place like what they do in some of their lenses. Good thing they didn’t because it is such a pain to do the ritual of applying solvents and waiting for it to work on the glue.

img_1643Carefully remove the rubber grip from the focusing ring by using a toothpick and running it under the whole circumference of the rubber grip to loosen it up and then carefully pull and pick on the grip until it comes off. Remember, go slowly so that you will not rip or tear this part.

img_1644Surprise! Scotch tape on an expensive lens! Nikon loves using cello-tape on Ai-S lenses for securing the focusing ring to the scale. This is where you calibrate the infinity focusing of this lens.

img_1645Simply peel off the cello-tape but before doing so please remember how the scale should be aligned with the focusing ring.

img_1646Next, unscrew the nameplate from the focusing ring by using a rubber or leather pad. This will give you enough friction to turn this part loose.

img_1647This lens has 2 helicoid keys. This was possibly due to the radius of the barrel so it needed 2 keys positioned at opposite ends to make sure that the torque/pressure is even. I am not a mechanical engineer so do not quote me on this.

img_1648Remove these screws to remove the helicoid keys. Interestingly, the screws on either side are not identical and is slightly different. To avoid any mistakes, just screw these back to their respective helicoid key for safe storage. I also marked one of the helicoid keys so that I will know which key should go to which slot later on reassembly.

img_1649It is time to separate the helicoid key but the stop-down lever is in the way! Simply rotate the helicoids until you get enough clearance and be careful not to separate them.

img_1650The helicoids of this lens is unusual for a Nikkor. Instead of the usual outer-central-inner helicoid order the central helicoid is the one outside and the two other lesser helicoids are positioned at the same place underneath it so the order now is upper-central-lower.

First, we remove the upper helicoid and mark where it separates from the central helicoid. If you forgot to mark this then you will spend plenty of time guessing where these should mate later during reassembly. Mine separated here – note the marks that I made.

img_1651The central helicoid separated at this place. Again, notice the light scratches that I made to remind me where they have separated and where they should mate.

img_1652Here is a clear  view of the inner side of the central helicoid. Notice that there are 2 threads machined unto it – one for the upper helicoid and another for the lower helicoid.

img_1653Here is the upper helicoid. Check out the 2 prongs that serve as guides for the helicoid key. Do not bend or damage these as they are casted as a cantilever and a pressure coming from the wrong direction may snap these things off.

Partial Cleaning (Objective):

The glass looks fine except for a few specs of dusts inside. I really do not want to open this up as much as possible but since I am halfway there I might as well try.

I opened up the objective to clean where the iris mechanism is because in my experience, this is where dirt seems to accumulate first most of the time due to some openings there and the mechanical nature of the moving parts found in it.

After the cleaning, I actually ended up with more specs inside than when I started. As I was closing the objective, some specs of paint came off and settled on the lens. I was not happy and this ruined my mood so I just left it there. The specs will not affect the images anyway and what’s a handful of specs inside gonna do anyway? It’s so tiny and you will hardly see them unless you took the time to look for them.

img_1654Carefully remove these 3 screws to separate the front assembly from the rear assembly.

img_1655It’s a very tight fit so be careful. Blow some air to remove the junk that has settled on the surface of the glass. Wow, just look at that beautiful iris!

Conclusion:

Every time I handle this lens I get really nervous because I do not want to damage this gem so just imagine how careful I was when I was overhauling this thing. I am quite surprised that this lens took me just under an hour to overhaul. I would not recommend this lens to any beginner because of the interlocking helicoids and the delicate nature of the optics. I would give this lens to a seasoned veteran like Jools Abel or David to service the helicoids if your’s got dry or gummy. Since the Noct-Nikkor 58mm f/1.2 Ai-S has a short focus throw I used a heavier grease that I reserve for wider lenses with short focus throw or longer ones that just need some damping. I wanted to have precise turns as well and a lighter grease will make me miss my focus, at f/1.2, you want to be as precise as possible.

The next illustration will show you how to calibrate the infinity focus of this lens. Just like most Nikkors or any lens with a helicoid and infinity focus for that matter, once you get the infinity focus right then your focusing scale should be accurate. Getting this wrong means that you will not be able to focus to infinity or focus past that point, this affects everything and the numbers on the scale will be off so they don’t mean anything much. Many earlier Nikkors do not have the infinity focusing adjustments because they were precisely built and the tolerances are so tight. I will calibrate the focus of every manual lens that I overhaul so that I am sure of my work because I am going to be the one using these anyway!

img_1656Reassemble the lens but leave out the cello-tape and rubber grip. Now, attach your lens to a modern Nikon camera with the autofocus confirmation dot feature on the viewfinder, it is not important if it’s a film camera or digital one. By the way, disregard the fact that I have 2x sided tape in the picture. My wife used all of my Magic Tape on my daughter’s poster so I had to improvise until I got a fresh roll.

Next, point your setup outside the window and focus on something that is really far like a building or a tree that is 4km or further. When you see the dot light up then that is where your infinity point should be. Be careful not to move the focusing ring and move the scale so that the infinity mark is squarely on top of the black confirmation dot on the DOF scale found on the chrome grip.

Keep this configuration and put a short strip of tape to secure it. Go test it again and see if the focus is still accurate and if it’s still good (a blinking dot is close but not good enough) the you can go ahead and tape the scale to focusing ring. Once that is through, check if 1m is indeed 1m in the scale by focusing on an object that is 1m away from you and check the other ones while you are at it. For me, I check for 1-5m since these are so important to me when I am taking pictures at the street. When all is good, reinstall the rubber grip and give yourself a pat in the back!

So, how do you like this blog post? Did it scratch a big itch inside of your heart to see what is inside a Noct? I do not know about you but it sure satisfied me a lot! As far as I know, this is the only article on the net that deals with a Noct’s repair. I tried searching before I began working on this one but I found nothing, even on the Japanese sites. With that statement I hope that somebody in this planet will find this useful and help them with maintaining a family heirloom. I got this lens from a dead person and I am sure that this lens meant a lot to him and to honour him, I will take good care of this lens myself. True, it wasn’t given to me as a gift and I had to pay for it with a relatively high sum by my standards but this can only be explained by a true Nikkor aficionado.

Thank you for dropping by my blog and if you liked this, please share this to your friends and “like” the facebook page to get alerts each time something new is posted as well as to interact with other people or to ask questions to me directly. Keep healthy, 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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16 Comments (+add yours?)

  1. Trackback: Internet Nikon Repair Resources – My Take on Photography and Diving (Underwater Photography Mostly)
  2. Garry Watterson
    Feb 18, 2017 @ 11:19:47

    G’day Ric,

    I have an 58mm f1.2 NOCT which has a broken rear lens element. Serial No. is 188180. It appears the clamp/glue gave way, probably from an unknown knock and the rear element fell out when the lens was being put onto my camera during a night time shoot. Found the broken element on the ground after not being able to focus.
    Any chance you or any contacts may have damaged NOCT’s that still have a good rear element? Probably a long shot that one from another lens will work but I used this lens often on night shoots and it is worth repairing!
    Thanks for an interesting article although I’m not about to dismember the lens.

    Kind regards

    Garry

    Reply

    • richardhaw
      Feb 18, 2017 @ 11:22:22

      Hi, Garry!
      Junk NOCTs are rare. These lenses are almost always very well taken cared of for obvious reasons. If you can, can you show me the extent of the damage and let’s see if we can glue that thing back together? I believe that the back is a single element and not a doublet. Ric.

      Reply

      • Garry Watterson
        Mar 30, 2017 @ 06:22:50

        G’day Richard,
        Sincere apologies as I have only just found you reply. Guess I need to tick the ‘notify via email’ box.
        Here’s the image showing the extent of the damage…definitely unrepairable. I’ve looked at the rear elements of the 50 f1.2 and the 55 f1.2, but although they are very close there are differences.
        Still keen to get this repaired if you locate anything or you know anyone at the Japanese Nikon lens factory.

        Kind regards

        Garry

        ps. Appears I am not able to add the image..anyway the lens broke in half with big chunks knocked off each side.

      • richardhaw
        Mar 31, 2017 @ 05:34:31

        Hello, Garry!

        Glad to hear from you again! I am not very optimistic about the transplant because there is a huge chance that the element will not jive well with the rest. I tried swapping elements on some of my lenses (even with identical models) and most of them simply doesn’t work. Your best option as of this moment is to look for a junk so you can transplant the whole objective. Junk NOCTs are still pricey by the way. Ric.

  3. Steven
    Mar 29, 2017 @ 23:54:16

    Hello,

    I have this lens. It was a gift from my dad. According to him, in his time he’s had to recover it from the bottom of a river. After that, back in 1984, he had it repaired, but he doesn’t know what was repaired exactly. All he knows is that it worked fine for him for years after.

    It’s produced some great pictures for me. It’s a very interesting and a very different style, and I’ve really enjoyed using it. But since I’ve learned more about it and about photography in general, I’ve noticed that I can’t change the aperture. That seems like something I should have noticed right away, but I’m a completely self taught photographer and I didn’t start looking into aperture until I got this lens.

    I’ve had this lens for a while now, and I’ve tried reading about it but there isn’t much out there about it and I end up just getting frustrated and shunning the lens for a while out of defeat. When I took it to our local camera shop, they were able to confirm that the aperture wasn’t changing when turning the aperture ring, but they had never seen this lens before and didn’t know what to tell me other than that.

    I’m definitely not going to attempt disassembling this lens. But I’m also weary of sending it off to have it repaired with as precious of a lens as this is. So I’m not sure what to do about repairing it. I was just curious if you have any experience with dysfunctional aperture rings and what can be done about it? Or if I’m just going to have to live with this lens set at a mystery aperture until I’m experienced and brave enough to attempt disassembly and reassembly?

    Thank you,

    Steven

    Reply

    • richardhaw
      Mar 30, 2017 @ 02:43:29

      That’s quite a story, Steve!
      There can be many things that can go wrong with that but the easiest culprit is a lost screw. Look at my teardown and see if there is anything missing amd if the blades are still there. If the bearings are gone then you would need a donor lens. Use a torch and look at it and see. With the correct set of drivers, you can remove some parts of the lens enough for you to make a diagnosis. Ric

      Reply

  4. Vishal Arora
    Apr 24, 2017 @ 16:14:01

    Richard, I just acquired a NOCT and though the item is absolutely visibly perfect including the aperture ring with no scratches, fungus, haze, etc. I did notice a bit of shake/vibration when I hold ONLY the Focus Ring. If I hold both the focus ring and the outer ring of where the filter screws in, then nothing. Just wondering if there should be a very small amount of rattle? I mean, very small? Thanks.

    Reply

  5. Vishal Arora
    Apr 24, 2017 @ 16:47:32

    Richard, thank you for confirming. Do you think a lens element could be loose or something of that nature if there is a very small amount of shake/rattle? It is not a grinding kind of sound, but something does move it seem. Thank you.

    Reply

  6. Trackback: Repair: Nikkor-S 5.8cm f/1.4 Auto | Richard Haw's Classic Nikkor Maintenance Site
  7. Anthony
    Jul 17, 2017 @ 23:48:42

    Hi Richard. Thank you for this blog. I had the courage to purchase a Noct with issues for a very reasonable price. After looking through it and using your blog as a guide I am now inclined to believe that the rear element may have been mounted the wrong way at some point during a repair. As I don’t have another Noct to compare to I was wondering how convex the outer part of the rear element is. The lens I have seems to be almost flat. I am having focus issue in that all shots at 1.2 have too much glow, very little contrast at the focus point. Also, when I tried to adjust the lens for infinity but the entire optical seems to be too far forward when I got the best focus. The ring that keeps the optical block in place is about 2mm too far forward. Thank you.

    Reply

    • richardhaw
      Jul 18, 2017 @ 00:01:41


      Hello, Anthony. Glad this was useful for you. Check Mr. Mansurov’s png above, the rear element is the only ambiguous one. this part is secured very well to the housing so I doubt the repair guy messed around with this and the rear is also sealed if I remember it correctly. You can try and see if it was indeed tampered. If it’s not then the spacing of the elements are probably off. You will have to collimate this manually. Ric.

      Reply

  8. Anthony
    Jul 18, 2017 @ 15:38:07

    Hi, Ric. Thank you for the reply. I think the lens was disassembled at some point. The rear element has a nick that was caused by a botched attempt at fixing the lens. From the inside, the retaining ring for the inner elements of the rear optical block seems to be thread-locked. It does seem the rear element is pretty much set with the rear metal housing it being mounted in reverse is a very low possibility. I am now inclined to try to disassemble the rear optical block and try setting everything back in place.

    Reply

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