On 1 Nov 2001, at 14:11, Kent Gittings wrote: > Acetone is the best lens cleaner. Make sure you get it pure not something > like nail polish remover. That and Q-tips will get anything off a lens > without harming the coatings. Acetone will require you to rub it with a > clean dry Q-tip if the element is dirty enough so that the acetone leaves a > streak when you use the fluid. Kent Gittings
I'm with kent here, but I use Chemtronics Low Lint Cotton Tips which are like a long single ended Q-tip with a wooden shaft. The are specifically designed to clean optical assemblies and other equipment, I bought 1000 (in packs of 100) for the equivalent of about US$30, not bad value. I have used acetone however it can cause damage to plastic or painted surfaces so I usually use pure isopropyl alcohol purchased at a local pharmacy. I have found the alcohol to be little less problematic with plastics but it can still affect some inks but both solvents seem to have similar capabilities WRT lens cleaning. The method that I use is to initially saturate a swab and paint over the whole glass area to be cleaned then I get a dry swab and dry off the lens, you will most probably be able to see streaks on the glass, these are contaminants and are usually greasy so every step I use a new swab and even if it looks clean I put it aside now relegated to less some other demanding cleaning task in its second life. I have found that often there is a build up of greasy gunk in the interface between the glass and the edge of the lens barrel, a lens might look clean then as the swab comes from the edge it will draw a great line across the coating, once the swab has contaminants on it it will leave streaks. The most effective method to finish the surface is to use the swab on its edge and gently roll it so that the remaining contaminants are dispersed across its surface rather than concentrated in one area. Well I didn't intend to write this much but there it is, if you persist you will have a virtually absolutely clean surface and you can re-assemble your lens knowing that there isn't any gunk inside (or outside), you might go through 10 or 20 swabs though. The last point is that when doing lens repair it is a good thing to have compressed air or nitrogen handy to blow the dust out of the lens before it is re-assembled :-) Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://www.ozemail.com.au/~distudio/publications.html - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
