I've used pure isopropyl on filters without any problems. Note that
the isopropyl you get at the drug store isn't all that pure. I use
technical grade (about twice the cost, but no wintergreen oil or other
mystery stuff in it.] I get my technical grade isopropyl at Fry's
Electronic, but I found an old post right on s.a.a. that says Radio
Shack sells it as well.

At Fry's, look for PureTronics Technical Grade Isopropyl alcohol,
99.9% ultrapure. $6.99 for 32oz. Like I said, not cheap.
http://www.puretronics.com/distributors.htm

Cotton balls are considered better than lens cleaning paper. Generally
the procedure (at least for filters) is to blow off the dust, then use
a cottonball dipped in the alcohol to do the first wipe, then toss it
and get a clean cotton ball and repeat. What you are trying to do is
not to rub the surface of the glass with dirt. I have a scuba tank of
compressed air (relatively cheap if you use canned air in volume). I
you use the air from a canned duster, make sure you keep it level so
none of the refrigerant flys out. The claim is the cold refrigerant
could disturb the glass surface.

Lumicon has filter cleaning tips here. No mention of diluting the
alcohol.
http://www.lumicon.com/faq-c.htm




"MD" wrote in message news:xyard.213354$df2.119733@edtnps89...
Is it true that a 50% solution of 99% isopropyl alcohol and distilled water
(1:1) makes
a good lense cleaner? Does it affect coatings?