FSU lens coatings soft?

[ChrisPlatt]

In a recent conversation with a FSU emigre at work he cautioned
me not to clean my I-61 L/D lens as the coating is easily damaged.

Descriptions of used FSU lenses for sale often mention decoating,
cleaning marks, etc. In general, are FSU lens coatings delicate?

TIA,
Chris

 

[ed1k]

I don't think so. Just don't use t-shirt or a sleeve to rub dirt off the glass. Usual FSU practice was to breath on the lens and use cotton wool - not so great for any coating... Sometimes people used solvents not designated for coated lens, sometimes they used toilet water known as eau-de-cologne with a lot of scent oils - that's why there are so many damaged lens around. Personally I think breath on the glass is OK, but you have to drink a glass of russian vodka before 🙂

FSU emigre,
Eduard.

 

[clarence]

I try not to touch the surface of any lenses, FSU or otherwise. Even the best coatings will get damaged if you're not careful. Just use a blower.

If you breathe on your lenses, you'll get moisture into them. Not a good idea, really.

Clarence

 

[zhang xk]

I noticed that there are far less cleaning marks on my 4 J-3s than I-22 and I-50s. These may have hard coatings. But it could be that these are more expensive optics, and people took more care of them. Other people may confirm my observation.

Zhang

 

[Xmas]

Chris

Coating technology has improved from Cooke's discovery in 19 century through the initial Zeiss process to latest technology.

An early Ru lens will have had a near copy of the origional Zeiss process, the latest 80-90 proably more sophisticated - cheaper but more effective.

Even if the coating is really hard giving it a friendly rub with quartizite wont necessarily be a good idea.

The Zeiss origional coating was a lot harder then the early optical glass but not necessarily as hard a quartizite.

I'd not clean my lens unnecessarily, get a deep lens hood instead. If you need to clean it wait till you get indoors use:-

- a blower bulb, first,
- dab on some proprietary lens cleaning organic fluid
- wipe off with a new micro fibre cleaning cloth
- store cloth in zip lock bag

If a mark wont come undone try a water based lens cleaning fluid, I've had stains that one needed to employ water based repeatedly...

Some of my older J3 from early 50's are like ground glass, clearly mistreated, -the coating may have been softer. I've a '53 that is good enough to use contra jour with a lens hood, it may have been looked after.

Noel

 

[Valkir1987]

The manual of my Zenit E says the lens can be cleaned with water, ether or eau the cologne. Defenitely not the right way to clean a lens... :| When available I always use a UV filter and a lens hood to protect the lens from dust and such things. I've seen awfull fingerprints on compact camera's and digital cameras.