Howard, I don't own an ETX, but I seem to recall reading that the corrector was designed to be easily unscrewed by the consumer for cleaning. Modern coatings are very tough, and if you use the same cleaning solution that the optometrist sells for, say, my $400 bifocals (grrrr), with some lens tissue, you should be OK. Just apply a dampened tissue and rub GENTLY, then dry with a fresh piece of tissue. You could also use one of those modern micro-fiber lens cleaning cloths. Any techniques used for camera lenses will be OK for the ETX as well. Just be very careful with the secondary. Aluminized coatings are not as forgiving as lenses and should not be rubbed. There should be quite a bit of owner's posts on the Web about this, as well. See if you can locate an ETX user's group. Great price, well-done! In a message dated 3/10/2007 12:02:03 AM Mountain Standard Time, sumoetx@yahoo.com writes: OK everybody, time to get this list a bit active I hope. I recently bought an ETX 90 for the tidy sum of $80. That's not relly necessary to tell you but I wanted to brag a little. I already have one but I'd like to give it to my son as a present since his interest in astronomy is increasing. Anyways it has a few very distinct fingerprints on the outer and <GASP> inner corrector lens surfaces!! I know I almost cried when I realized that they were inside. I've perused the web for cleaning tips solutions etc, specifically Weasners Mighty ETX site which is amazing by the way I've followed that site for over 10 years. I'd like to know of any local wisdom, tips, in this area and possible suppliesand/or ingredients to buy. Any and all help would be very welcome. Thanks! Howard ______________________________________________________________________________ ______ <BR><BR><BR>**************************************<BR> AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com.