Cleaning Glass on old lenses

[David Aimone]

Sincere apologies for asking a question that's probably been answered before, but a search for this brought up <everything> but the answer... :rolleyes:

What is the best way to clean the glass on older lenses (assembled)?

Coming from the digital camera world, I would have just used a combination of a blower, lens pen or special cloth/paper with solution.

But these lenses are much older, and to me, much more valuable (even if they don't cost more). So the lenses that I have are all pretty decent, but they are collecting more dust and other contaminants from all sources (pollen, dust, salt air, etc.). I don't want to scratch them.

What is a safe, gentle and effective method for regular cleaning?

[domaz]

If they are uncoating its easier to clean than modern lenses- just use the methods you always use. If you have a lens with an old coating like the Kodak ektars I would be hesitant to even touch them unless it's absolutely necessary. Those coatings are very soft.

[David Aimone]

I have some old brass lenses, I assume uncoated. I will gently air dust, then wet clean.

Also, what about newer old lenses (Rodenstocks, Nikkors, etc.) from the late 20th century?

[IanG]

If they are uncoating its easier to clean than modern lenses- just use the methods you always use. If you have a lens with an old coating like the Kodak ektars I would be hesitant to even touch them unless it's absolutely necessary. Those coatings are very soft.

Some uncoated glass is extremely soft, usually 1930's when newer glasses allowed faster lenes, particularly the glass used by Leitz for lenses like Summar's, and Zeiss used similar glass in some of their lenses.

Most coated lenses have harder glass but yes some coatings can be soft, so cleaning with a liquid cleaner is safer & less abrasive. It's surprising just how much dirt can have accumulated on a lens, particularly when previous cleans have just pushed the dirt to the edges.

Ian

[David Aimone]

The older lenses are probably 1900 or earlier; the newer probably at least 1970 onward. I'm just looking to do this safely.


Some uncoated glass is extremely soft, usually 1930's when newer glasses allowed faster lenes, particularly the glass used by Leitz for lenses like Summar's, and Zeiss used similar glass in some of their lenses.

Most coated lenses have harder glass but yes some coatings can be soft, so cleaning with a liquid cleaner is safer & less abrasive. It's surprising just how much dirt can have accumulated on a lens, particularly when previous cleans have just pushed the dirt to the edges.

Ian

[Dan Fromm]

If they are uncoating its easier to clean than modern lenses- just use the methods you always use. If you have a lens with an old coating like the Kodak ektars I would be hesitant to even touch them unless it's absolutely necessary. Those coatings are very soft.Are you sure? Have you damaged Ektars by cleaning them or are you repeating old wives' tales?

I ask because I have a couple each of 101/4.5 and 127/4.7 Ektars whose coatings on all accessible surfaces seem as hard as the coatings on newer lenses.

[domaz]

Are you sure? Have you damaged Ektars by cleaning them or are you repeating old wives' tales?

I ask because I have a couple each of 101/4.5 and 127/4.7 Ektars whose coatings on all accessible surfaces seem as hard as the coatings on newer lenses.

No haven't personally damaged any true enough. My 203mm Ektar does have a ton of coating scratches though but it has an unknown history so who knows if it was bad cleaning that did it or just bad handling.

[Robert A. Zeichner]

The guidelines for lens cleaning are pretty simple:

1. First blow off any loose dust or dirt.
2. Use a soft piece of cotton cloth (old T-shirts that have been laundered a lot of times work best) to gently push off any more stubborn, but nonetheless loose pieces of crap that might resist the blowing.
3. Dampen a clean piece of that laundered cotton T-shirt with some good quality lens cleaning fluid. I use diluted Butylcelosolve, which you may have a tough time getting, but some clean acetone will work well if there are a lot of greasy smudges on the surface. If that is not available, some Kodak or Tiffen lens cleaning fluid works, although less effectively on grease. Gently wipe the surface and avoid getting the fluid near the outer margins where it could get down under the retaining ring.
4. Follow up with your breath and another clean section of cloth.

Alternatively, one of those micro-fiber cleaning cloths that Schneider and other offer will work in lieu of the cotton cloth.

This technique has worked for me for many years on all vintages of optics. The biggest danger is failing to clear the surface of loose, abrasive crap that will just scratch the coating or even worse, the glass when you start the wiping process.

[Fotoguy20d]

I find Ektar coating can scratch very easily - never dry wipe a dirty/dusty lens (old or new) - think sandpaper. I never clean my modern lenses - I clean the cheap filter I keep in front of it (but that's another thread with lots of argument potential). Someone will probably cringe at the way I routinely clean old lenses (and I've gotten some really filthy ones off the bay). I remove the cells from the barrel to whatever extent possible (if a piece of glass is permanently installed, use care with this method) and then wash them in windex with a paper towel. On a truly filthy piece of glass, I'll often rinse first in water, spray, let it run off, and then spray again - the less grit in the solution the better. Use caution around cemented lenses - try to keep the solvent out of the balsam (in some cases, perhaps just use water). And wipe with care. YMMV but its worked quite well for me.

Dan

[IanG]

I find Ektar coating can scratch very easily - never dry wipe a dirty/dusty lens (old or new) - think sandpaper.
Dan

That's the best advice.

With early coatings there can be issues. Some, like Dan Fromm says, are very hard. My early 1950's 150mm CZJ Tessar is as good as modern MC, in hardness and effectiveness - just rather blue, a cast if used for colour :D

But I have had lenses with soft coatings, that will polish off if cleaned dry. My 101?mm Ektar's OK but has cleaning marks so some things soft.

Ian

[Michael Jones]

Are you sure? Have you damaged Ektars by cleaning them or are you repeating old wives' tales?


Not a wives’ tale.

First, most of the Ektar coatings are already damaged from age and careless cleaning and are more susceptible to being worn down by overzealous buffing (just like feathering a paint edge). Compared to a modern coating, Ektar's Lumenized coatings damage easily. It is imperative you have no dust on the lens, use a paper such as Kodak lens cleaning paper, and use the lightest of pressure when wiping the lens.

You can also use collodion to clean delicate surfaces. Pour it on, let it dry, and peel it off. This is how telescopic optics/lab tools are cleaned.


Mike

[goamules]

When I clean glass, mostly older, uncoated vintage lenses, I

- Always use a fluid between the tissue and glass.
- Drop a couple drops of fluid on the center of the glass, lay the tissue into it.
- Don't let that fluid run to the edge if there is a balsam cement line, or metal fittings.
- Put no pressure on the tissue, just let the bead of fluid hold the tissue down for pressure.
- Start in the middle, and turn the lens as the tissue is moved towards the outer edge.
- Only use that tissue for one cycle, discard.
- Use at least 4-5 tissue pieces, more for a really dirty lens.
- Be very careful at the edge of an assembled lens, that's were all the dirt is collecting.

If a lens is an attic find and can be disassembled, I'll sometimes rinse the glass in a plastic tub full of soapy detergent and water, but I'm careful not to rub the glass ever. I found the glasses cleaning tissues sold at Lencrafters work well. You can cut many 1" squares from one tissue, and they don't seem to scratch. Especially with my method.

[Frank Petronio]

I have a Thomas Tomby camera repair book and it shows him using Windex and Kleenex on customer's lenses ;-)

I suspect any older uncoated lens would be fine, you could use anything soft and wet really.

Those Lenspens are pretty cool to use if you have something to buff out. But more and more, I won't clean the lens unless there is something obvious on it, a smudge or smear doesn't warrant it.

[David Aimone]

Thanks everyone for the variety of answers. I think I can extract a best practices from them. I will tread carefully with these wonderful opitical devices, both aged and modern.

[Michael Jones]

I suspect any older uncoated lens would be fine, you could use anything soft and wet really.



Pop Quiz:

How many openings has Frank given us for additional thoughts with this comment?

Mike

[Fotoguy20d]

[QUOTE=Frank Petronio;617035]I have a Thomas Tomby camera repair book and it shows him using Windex and Kleenex on customer's lenses ;-)

[\QUOTE]

I wouldn't use kleenex type tissue - it creates too much lint. Another thing, the tissue I have contains aloe (I think its puffs) - you don't want that on your lenses - its bad enough on a pair of glasses.

Dan

[steven_e007]

There are lots of cleaning methods that can work - and some good advice here.

Golden rules are:
1. First remove dust and loose particles with a blower brush etc. I use a soft paintbrush after this, too.
2. Always clean WET. Never rub with a dry cloth or tissue.

Personally I always use cotton wool and roll my own cotton buds on a wooden stick - just my preferred method.

One thing I disagree with. Please DO NOT use acetone. It is a good glass cleaner (opticians and optometrists use it for spectacle lenses) but it is also a great solvent for paint, enamel, laquer and for the balsam between lens elements.

One set of instructions I've seen for re-cementing lenses with separation or mould in the balsam recommends using acetone to separate the cemented lenses!!!

[Lynn Jones]

If thay are uncoated don't touch them, the self coating will come off.

Lynn

[Ty G]

So, wet cleaning with no acetone or lens cleaning solution. What do I use to wet clean?

By the way, hey Mike J. hope everything is well on your end. Sometimes miss shooting the bull with you.

[Brian Stein]

proper lens cleaning tissue. readily available from any optician. dont be sparing with it. one swipe and ditch.

[Alan Butcher]

I find this paper by Schneider to be a good reference for lens cleaning.

https://www.schneideroptics.com/pdfs/whitepapers/lens_cleaning.pdf


--
Alan

[Peter De Smidt]

Use a very soft brush, a sensor cleaning brush is ideal, or blower to get as much off of the lens as possible. Take a sheet of Kodak lens cleaning tissue. Roll up into a tube. Rip (don't cut!) the tube in half. Put a drop or two of lens cleaning fluid on the ripped end of the tissue. With a rolling motion, lightly move the wet end against the glass. You put one edge down first, and slowly move the tissue forward, pivoting your hand while you do so. The idea is to not drag tissue that's picked up anything over the glass. Use each "swab" once and discard.

[community1313]

Hello, I often find my newly purchased lenses to be dirty and foggy, sometimes even with fungue, when the lens has been kept in a box it's no better since it's keeps the humidity. It is not dramatic. I put them under the faucet and clean them with dish soap but avoid touching the glass, then I open the barrel and get the glass out, I suppose this needs some expertise, the edge of the glass can be thin and fragile and the barrel does not always unscrew (the steel ring that is used on garden hose comes in big diameter and makes a good tool to hold he barrel, if they are not long enough use two!)
the reason why you must not clean the glass inside the barrel is that the hardest debris are going to be stuck between the glass and the barrel and when you use that tissue you will collect it and damage the glass, if you use lens tissue use it once and put it in the washing machine! now I use paper, I found this big rolls we use for garage work and it's the best for cleaning lens because after I wipe the glass once I throw the piece of paper away and have less chance to have collected hard debris. when the paper is wet it's soft, when I finish I use dry paper but you have to make sure your glass is hard.."le Français" makes nice rapid rectilinear but the glass is very soft..I saved two Hermagis lens from fungue using paper and alcool, I polished the lens because after cleaning it with soap and water some cloudy traces where left from the fungue eating the galss but alcool and paper got rid of it. I use pharmaceutical grade, keep the JB for your cocktail!
Naturally this is only for very dirty lens and non coated, the regular cleaning I keep my lens in a dry storage and blow the dust from them or use an antistatic film brush,
coating is very sensitive to salt, I shoot a lot near the sea side and it's no crime to adapt a modern uv multicoated filter to protect your lens. (it did that on my veritar, the coating was already damaged but the lens preformance is just fine).
conclusion: avoid cleaning your lens and if you do the most dangerous zone is between the glass and the barrel, but with air spaced lens it's important to clean them because with time they always get foggy..