Film-Tech Forum ARCHIVE: Lens cleaning tips

This is topic Lens cleaning tips in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=004776

Posted by Robert Throop (Member # 61) on 04-11-2003, 12:09 PM:

I've acquired some lenses that had been installed in a damp cellar and have developed some type of mold on the glass. Does anyone have a suggestion on how to safely clean them without damaging the coating?

Posted by John Pytlak (Member # 331) on 04-11-2003, 12:13 PM:

Dwight Lindsay may have some suggestions. Here's Schneider's white paper on lens cleaning:

http://www.schneideroptics.com/info/white_papers/lens_cleaning.pdf

And Edmund Optics:

http://www.edmundoptics.com/TechSupport/DisplayArticle.cfm?articleid=265

http://www.edmundoptics.com/TechSupport/optics.cfm

Posted by Scott Norwood (Member # 30) on 04-11-2003, 04:40 PM:

Has anyone ever tried _baking_ lenses in a warm (~200 degrees) oven? I've heard of people doing this with success when the problem is glue separation, but I'd be fearful of trying it myself without personally talking to someone who had found success with this method.

Obviously it wouldn't work with any lenses that have plastic parts (are there any projection lenses that do?) and the lens would need to be removed from its collar to avoid the possibility that the lens would expand faster than the collar and possibly crack.

Posted by Aaron Mehocic (Member # 15) on 04-11-2003, 05:21 PM:

Scott:

In regards to your first question, yes, I have heard of this and it was suggested for me to do this by our booth tech some years ago. He recommended 120 - 140 degrees F. Like you I am uneasy about doing that without some supervision or a real clear understanding just what exactly I'm getting into.

Posted by Richard Fowler (Member # 893) on 04-11-2003, 05:30 PM:

I had an old timer who purchased old lenses who would heat them in cooking oil to dissolve the cement, disasemble and put them back into service...very labor intensive but he had plenty of time being retired [Smile]

Richard Fowler
Kinoton America Inc.

Posted by Dan Lyons (Member # 1454) on 04-12-2003, 01:55 AM:

Robert, what make and model are these lenses? If there is mold on the inside and out, it may be a lost cause.

Danny

Posted by Gordon McLeod (Member # 33) on 04-12-2003, 10:05 AM:

Certain molds also attacked the coatings actually etching the glass
Berthoit lens seemed to have that problem the worse