Does anybody know a source for micro grub screws? The best I can find is del-screw.com, but it seems to be japanese and does not offer retail distribution

@Mikelinn & @Tscheckoff, thanks so much for posting these videos as it gave me the confidence I needed to open up a minolta 50mm 1.7 that I bought for $30 at a pawn shop recently, and had a few black specs on the inside of the lens that showed up in the right light. I used circlip plyers and not scissors, and a few drops of zippo lighter fluid. The lens opened up really easy and I'm so pleased cause I like this lens a lot. Cheers.

Hmm. I also recommend to use a lens opener. Scissors are way to unsave. I also have one now - but within the following videos it was also possible for me to open up the lenses with a screwdriver. Also not the safest way - but way easier to control than a scissor. Btw.: The first video is more general cleaning - The 2nd one is more detailed about the Helios 44-2. Maybe helpful for someone out there.

Laughed my a%% off! That's not the correct way to clean a lens!

1st get yourself some proper tools: http://www.ebay.com/sch/Cameras-Photo-/625/i.html?_from=R40&_nkw=lens+tool Don't use a pair of scissors, did you notice the bandaid on his thumb?

When you're done, you might want to check your lens on a collimator...

@tetakpatak, yes. Spelling is not always my strong point.

@mee is this what you meant? (Naphtha)

@svart thank you very much this detailed technical infos.

@balazer I've tried/tested cellulosic thinner for coatings. Glass was more transparent. But attention! For your hand-skin and other lens parts. Solvents is carcinogenic!! And you can get drunk!

Please watch it for smile and learn moree:

Removing the coating from just one element surface will not have much of an impact. I have a coating in bad condition, and a neutral density spot filter that I want to remove.

How can I remove a lens's coating?

@simurg The acetone should not be harmful for real coatings, as those coatings are hardened chemicals bonded with the glass.. That's not to say that there aren't cheap lenses with some kind of sprayed on coatings that aren't fully bonded with the glass and might come off with acetone.

With that said, I have to reiterate that using acetone is great for cleaning the glass itself and the anodized aluminum parts, HOWEVER, you MUST make sure that it does not come in contact with any PAINTED surfaces, plastics or rubbers. I also only really use acetone for cleaning the lens elements themselves before reassembly. Once reassembled, I'll just use ordinary lens cleaner (usually iso-propanol) on the outer lenses. Even then, use canned air to blow any possible dust off the lens before you wipe anything on the lens! You never know when that piece of dust is actually a piece of dirt or something that can scratch your lens! Always use a new cotton ball or cleaning wipe on EVERY swipe. Once that ball has gone across the surface, it's contaminated with oil and every swipe will only smear what you picked up the wipe prior. Cotton balls are cheap, so are solvents. Cleaning glass properly can take minutes to hours per element, especially if the glass has oil on it.

The blades in older lenses are usually black anodized aluminum, as are the housings for the blades and such. If you can get the assembly out and remove the glass, you can soak the aperture assembly in pure acetone and rinse it out with clean acetone. I've also used automotive brake cleaner for these things but it can leave a residue. Just make sure that there are NO particles of grease left anywhere or it'll continue to migrate and stick the blades or get all over the glass. Try washing the assembly out before you dis-assemble if possible. Those assemblies are a real pain in the ass to put back together if you are trying to figure it out without an example or instructions.

I'd also use clean latex/nitrile gloves without the powder, you can get these at automotive parts stores too. Whatever solvent you use can actually wick the oils from your fingers into your cotton balls/towels and get grease on your lens making it harder to clean.

If you decide you'd rather use alcohol to clean the glass, make sure it's the purest alcohol you can get, preferably Iso-propanol. Other alcohols have too much water in them or, like ethanol, are hydroscopic and will absorb water from the atmosphere and cause smearing. Almost all alcohols will leave a slight residue, though.

On plastics, I might go a different route. I'll use an industrial degreaser (like Greased Lightning or others) and wash them with a toothbrush and clean water. To dry, I use canned air to blow the water off. Be careful though, you might still have residue because surfactants(the active part of degreasers) don't work as well as solvents. Don't let the parts air dry or else you'll have a lot of residue on them. Also, use gloves here too, mainly because the degreasers will dry the hell out of your hands and can actually cause your skin to shrink and crack if you let too much get on your skin! I know from experience!

@RRRR, the meyer optik would definitely be a lens worth taking time to service! Love that bokeh monster..

On that note, if you do need cheap lenses for test diy take aparts, try searching for old 135mm f2.8 lenses (many brands to choose from)...there's many on ebay that don't even sell for cost of shipping!
I bought a no-name Sonagar 135mm f2.8 because it had 10 aperture blades, but they were super oily and when I took the lens apart, found one of the blades was bent which threw the rest out of wack, and so now I use the lens without any blades! (super soft, but wonderful bokeh, best not in sun).

@CFreak the easiest thing, and highly necessary for most repairs (unless you know the design type well) is to find a guide online for a specific lens. You have to do a bit of research and make up your own mind wether you want to go ahead.

Flektogon 35mm mc are notoriously easy to service + they have an easily accessible helicoid that still has a similar design like many other vintage lenses = a good place to start for understanding how to disassemble and reassemble helicoids.

I did a full service on a meyer optik 135mm f2.8 that had a stuck aperture blade. It took a while, in particular the helicoid was a bitch to put together since I did not take enough care during disassembly.

I would not go into something too complicated as I don´t have any proper "shop" to work in, nor do I have all the proper tools, like wrenches for retaining rings. (I use calipers instead = a bit risky).