TN 0015: How to Clean TASS Filters

Author: Michael Richmond
Date: 960611
Revision: #1 960611
Key Words: filters, optics

The first step one should try is the least dangerous: for loose dirt, one can use a little squeeze-bulb device to attempt to blow the dirt off the surface. I have heard several people warn against using "canned air", due to the impurities it may have. A squeeze bulb is much safer.

For material stuck to the surface of the filter, one must be careful. I have talked to people at Omega Optical (802 254-2690) about the method one should use to clean the filters Bohdan has given to Tom for distribution with TASS cameras. They said one must be VERY careful, for the filters have coatings on the exposed surfaces. Here's what they recommend:

• 1. pour lots and lots of pure alcohol over the surface. With luck, the dirt and grime will simply wash away.
• 2. check the lens surface -- if clean enough, stop.
• 3. soak a lens tissue in pure alcohol. Drag the tissue over the surface of the lens, allowing the weight of the tissue itself to bring contact between tissue and surface. Do not apply any additional pressure.

I am beginning to feel that it may be best in many circumstances to leave a little dirt on the filter surface.