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Nikon AI lens maintnence


mark45831

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I have seen several of the Ai Nikon lens that I would like to pick up, but many times even though the condition of the lens itself would be very good it would have a, sticky or oil on the blades and haze/fungus. Can these problems be cleaned up or is the haze/fungus something that cant be removed?
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Fungus can be cleaned up, but often times the coating damage left in its wake is irrepairable. Will you notice it? Maybe or maybe not, but I prefer not to take chances.

 

Oily blades aren't common in my experience on AI lenses, but some AI-s lenses are notorious for the problem. I agree with Sandy in general though-for common lenses it's USUALLY not worth the cost of cleaning and instead just buying a lens without the problem is best.

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I have seen several of the Ai Nikon lens that I would like to pick up, but many times even though the condition of the lens itself would be very good it would have a, sticky or oil on the blades and haze/fungus. Can these problems be cleaned up or is the haze/fungus something that cant be removed?

 

I would be wary of purchasing a lens with fungi, which can etch the glass leaving permanent damage.

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Oily blades can be cleaned (at a cost by a camera tech), but fungus is for all practical purposes a death sentence.

 

The problems with fungus are:

- Fungus can spread, to your other lenses. It is, a fungus. If the spores get out of that lens . . .

- Has the fungus etched the glass, and how bad?

IMHO, not worth the trouble.

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Thanks for all the input,, My thought with this is if I got a lens dirt cheap and cleaned it up myself, more of DYI project, I wouldnt drop any $$$ into them, something I could. afford to throw into the trash if it didn't turn out right, Thanks again, good info for when I do buy used lens to keep in mind..
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Thanks for all the input,, My thought with this is if I got a lens dirt cheap and cleaned it up myself, more of DYI project, I wouldnt drop any $$$ into them, something I could. afford to throw into the trash if it didn't turn out right, Thanks again, good info for when I do buy used lens to keep in mind..

 

I would not attempt to take the lens apart to the degree needed to get at the aperture blades.

If it is between elements, then you will need an optical bench to put it back together properly.

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Agree with previous advice: get a clean lens in the first place. Economize on exterior barrel condition if you must, with glass condition the priority. Other than a few fast cult lenses (like 35mm f/1.4, 50mm f/1.2, 85mm f/1.4 etc) most AI and AIS lenses are common enough that you don't save a heck of a lot by buying tainted glass with a plan to repair it. While a skilled DIYer can repair most Nikkors, they aren't nearly as easy to open up as they look: haze or fungus between elements can be very difficult to access in some of them. Check those Richard Haw links: just getting the nose off an ordinary 50mm AI Nikkor is a royal PITA.

 

FWIW, I've rarely found fungus to be the bone-shattering nightmare its often portrayed to be. Sooner or later, most of us see it turn up in a previously-sterile, beloved lens. I've had to clean it (or had it cleaned professionally) from several over the years, and in each case the nastiest part was getting access to the affected glass. Usually it simply wipes of with a bit of peroxide, never to return again, with no etching of glass. Occasionally a very faint, near-invisible rainbow residue spot will be left in the coating, which has no effect on anything (except potential resale price to anal retentive buyers). Sure, if the lens is so occluded by fungus that it looks like Spiderman had his teenage way with it, the coating is probably ruined and the lens highly contagious to other gear. But typical small patches of it that appear suddenly aren't life-altering if caught and cleaned promptly.

 

Haze, OTOH, often is a big problem. Half the time it wipes right off, half the time it turns the surface of the glass to sandpaper (or is so embedded in the coating it won't come off unless you remove the coating as well). It also has the annoying tendency to locate itself within sealed middle-element optical blocks. So yeah: hard pass on anything listed as "hazed".

 

If you wanna just buy a dirt cheap goner Nikkor to practice on, be sure you have a good selection of appropriate tools. I learned the hard way: makeshift substitutes will scratch the lens and cut your hand open. At minimum you need a decent spanner wrench with different tips, rubber stoppers for unscrewing front name rings, a good set of jewelers screwdrivers. Nikon lenses with cross head screws need JIS-specific cross head screwdrivers in sizes #0 and #00. Do NOT use ordinary Phillips screwdrivers on a Nikkor lens bayonet: you'll ruin the screw head and never get the damned thing open.

 

Nikkors with slot-head screws on the bayonet are the work of Satan himself: you will go mad trying every imaginable standard screwdriver, all of which will likely ruin the screwhead because Nikon infuriatingly used non-spec slots and Def Con 5 level superglue in the threads to make certain nobody would EVER get these lenses open after they left the factory. It can be done, you figure out how after a lot of trial and error, but it takes enough effort to put your hands in a sling afterward.

 

If all you need to do is blow out excess dust or clean a small fungus, don't try for full disassembly: consider just using a spanner wrench to carefully unscrew and remove the rear element group for basic internal access. This is a LOT faster and easier, and avoids the trap of dislocating the aperture actuation levers. Of course, some lenses with large rear elements aren't amenable to this (since they have little to no clearance for the spanner wrench tips). Those will require removing the bayonet and aperture ring first.

Edited by orsetto
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Nikkors with slot-head screws on the bayonet are the work of Satan himself: you will go mad trying every imaginable standard screwdriver, all of which will likely ruin the screwhead because Nikon infuriatingly used non-spec slots and Def Con 5 level superglue in the threads to make certain nobody would EVER get these lenses open after they left the factory. It can be done, you figure out how after a lot of trial and error, but it takes enough effort to put your hands in a sling afterward.

 

Watch repair doesn't have that much in common with camera repair, but this is one area where a skilled watchmaker will likely be at an advantage.

 

In watch work, screw heads can be all over the place. A good watchmaker will learn to select a driver of the appropriate width and then shape the tip as necessary to properly fit the screw. Good screwdrivers have replaceable tips(and a new set of screwdrivers will usually come with several replacements in each size) and the tips are carbon steel soft enough to not harm most screw heads and to take to sharpening easily on something like an Arkansas stone. To be fair, my drivers stay sharpened for American watches and any sharpening is just to touch them up from wear, but I have spent a fair bit of time grinding one to the correct shape for a specific screw.

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Most of the optics in Nikkor lenses are in fixtures that screw back into place in the barrel. Mark the starting position of the group before taking it out, make sure it gets back to the same place. Some older lenses have retaining rings holding the glass element in place, not held in a fixture. Better lenses have a mechanism of sorts built in for centering the optics. Shoot a brick wall or some other flat object to check corner-to-corner sharpness in case of misalignment.
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I don't know what the situation is in the US but here in the UK I have never had a lens serviced correctly, even by Nikon themselves. Worst is sending it in for dry focusing as they come back with oil on the blades or sometimes completely seized due to too hard grease being used.
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I have had two AIS lenses serviced at Authorized Nikon [Camera] Repair in Morten Grove, Illinois. They were once associated with Nikon, but now operate independently, but with Nikon tools and parts.

 

The usual issue with AIS lenses is a sticky diaphragm. The blades must be cleaned of any oil or grease. The original grease was a true grease, which is oil mixed with a metallic soap, which forms a gel, keeping the oil in place. In time the oil bleeds away, into places like the diaphragm, leaving a hard, sticky residue. I believe Nikon now uses a silicone based grease, which does not have a liquid phase, and does not bleed or dry up. The first time was in 2001 or so, and still works like new.

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I don't know what the situation is in the US but here in the UK I have never had a lens serviced correctly, even by Nikon themselves. Worst is sending it in for dry focusing as they come back with oil on the blades or sometimes completely seized due to too hard grease being used.

Here in the USA, most of my recent lens service experiences---including APS---have exhibited some degree of incompetence. Wrong grease used, failure to adjust infinity focus, lens reassembled wrong, lens not cleaned internally, lens returned to customer in unusable condition, etc, etc.

Except Nikon L.A, who serviced my 17-35/2.8 and, 8 months later, the repair went bad and bricked the lens. Even though it was nominally past their 6-month warranty, they fixed it again fast, free and correctly. Seems like the technicians who knew how to service helicoids have died off or retired.

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Here in the USA, most of my recent lens service experiences---including APS---have exhibited some degree of incompetence. Wrong grease used, failure to adjust infinity focus, lens reassembled wrong, lens not cleaned internally, lens returned to customer in unusable condition, etc, etc.

Except Nikon L.A, who serviced my 17-35/2.8 and, 8 months later, the repair went bad and bricked the lens. Even though it was nominally past their 6-month warranty, they fixed it again fast, free and correctly. Seems like the technicians who knew how to service helicoids have died off or retired.

 

I sent my 17-35 to Nikon for a tune-up and re-grease as it was a bit loose/dry. Waste of money - it came back feeling EXACTLY the same if not looser but now the AF-S motor squeaks loudly. Now I just buy a working used example or new.

 

I sent one lens back twice and even then it was worse than another used one I picked up. The grease is always the problem - maybe because the service centres don't have access to the proper grease. New MF Nikkors feel wonderful and damped.

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New MF Nikkors feel wonderful and damped.

 

Unfortunately, this tends not to last more than ten years at most, and when manual Nikkors go "dry" its best to just get used to it and pretend you never felt the thrill of nicely damped manual focus. On the plus side, it could be worse: I'll take Nikon's dryness any day over the seized, heavy feel you'll get stuck with in many other brands of vintage MF lens. But I often wish Nikon had stolen whatever durable lube recipe Pentax used in their exquisite-feeling screw mount Takumars, or Konica used in their '70s Hexanons.

 

Some MF Nikkors have nice smooth damping that stands the test of time, but its a crapshoot. Thru many years and many Nikkors, my experience has been almost all the older scalloped-ring lenses below 105mm are dry and too easy to turn. Between 105mm and 200mm, the scalloped lenses run 50/50 dry vs really nice. The pattern was continued with the AI and AIS versions, but you have a slightly better chance of getting one below 105mm that isn't completely dry. The good news being, if you find one thats still well-damped today, it will likely remain that way indefinitely. Depending on the specific lens helicoid and lube used during a specific production run, the damping either evaporates within a few years or remains stable for a lifetime.

 

Helicoid re-lube service is indeed a lost art, tho I have my doubts it was ever really practical. I've spoken to several highly-regarded techs (factory trained, with decades of experience) about the feasibility of re-lubing several of my Nikkors, Zeiss Exakta, and Hasselblad lenses. Each gave me the same bit of wisdom: they would attempt it if I insisted, but the results are typically unsatisfactory (no change in feel, or unstable/negative change). The original damping in these lenses had a finite lifespan of around ten years, after that the lenses themselves may be usable forever but the helicoid "is what it is" and can't be restored to nice damping. Logic would indicate otherwise, you should be able to simply clean and re-lube, but in real life some brands of helicoid are voodoo.

 

This is of particular concern with old silver or black all-metal Zeiss lenses like the 58mm Biotar for Exakta/M42 (or pretty much any lens made for the Contarex): they often get stiff and heavy to the point of being really unpleasant to use, but there's nothing to be done about it. And newcomers to vintage Hasselblad need to prepare themselves: believe it or not, the atrocious heavy effort required to focus the original silver or black metal Zeiss "C' lenses was baked-in and intentional from the start. It cannot be made nicer: this is one of several Hasselblad torture features that you grudgingly tolerate to use the nice glass. The later CF lenses are barely any better, beyond at least having rubber focus grips instead of finger-shredding serrated aluminum (!). The final CFi/CFe/CB versions have sweet easy luxurious focusing, but of course cost double the price.

Edited by orsetto
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