As alternative to wiping a lens surface either dry or by addition of solvent or cleaner-solution, coating the lens with a resin that after drying can be peeled off, including all dirt/stainingn is marketed:
I saw that stuff many years ago but never tried it. The older stuff was an eather based coloiden or someting like that. You smear it on, layer a gause into it.. when it dried just peel it off. It was very poplar with astronmers to clean their optics. It was also very very expensive.
I jsut use paint store denatured alcohol on a small pad, being carefull not to get it into the elements where it an take the blackening off the edges.
let me know if you get it n how you liked the results?
As alternative to wiping a lens surface either dry or by addition of solvent or cleaner-solution, coating the lens with a resin that after drying can be peeled off, including all dirt/stainingn is marketed:
A bottle of OptiClean (UK-made) bought in 1997 goes a long, long way. It cost me $25.00 at the time by mail order and is still in use (about 3ml usedcertainly you do not use it slavishly). I have used it on mirrors and eyepieces, brushing it on very lightly (but not edge to edge where it can break and become more difficult to fully remove) and using a small adhesive tab lightly pressed to lift it off when dry. It is said to be a co-polymer and smells suspiciously like nail polish remover (!). The side of the bottle is printed with warnings to avoid naked flames and inhalation (absolutely!). I don't have the original instructions with me but I believe it should not be used on multilayer coated lenses; I certainly do not (it was used last week to remove a stubborn oily stain from a Kenko Zeta UV filter). Might be worth researching.
EDIT:
This link was found during a cursory search to see if OptiClean is still made; apparently yes, and there are warnings that mirror my thoughts. http://www.cloudynights.com/item.php?item_id=551
I have a box of alcohol wipes obtained from the chemist called SkinPrep (photo); these work a treat and completely remove smudges. There are 4 in each of my bags at any time. I use the OptiClean stuff for studio-based maintenance.
I bought Opticlean in the late 90's for not too much money. It is the best cleaner I have ever used. The last time I checked the price a couple of years ago it was astronomical (over $100 a tiny nail polish sized bottle) and now I can't even find it online...
In hoarding used cameras I come across stains on lenses which are hard to get rid off (maybe polymerized fats from fingerprints). I had to use stronger solvents than usual (cellulose thinner) and rubbing to be successful.
A cleaner-film as the above should be successful with such stains to be an alternative.
My method of cleaning is brushing, soft wiping with soft paper wetted with aqueous cleaner and then wiping with solvent.
I find straight household ammonia works perfectly; better than alchohol because the ammonia also removes the static. Life is so simple sometimes. - David Lyga
I some times use scotch tape. Not the old style clear with sticky residue but the kind you get now for wrapping gifts. I put the tape right on the lens and gently push all the bubbles out and then peel it back off. Doesn't harm the coatings and makes the lens clean.
Dennis