Cleaning Focuser Surface Plane Mirro

[neil poulsen]

I have one of those Omega micro-grain focusers with the surface plane mirror. How can the surface plane mirror be cleaned, without hurting it?

[Robert A. Zeichner]

I used to clean first surface mirrors regularly when I was overhauling motion picture cameras for a living. At that time there were no micro-fiber lens cloths and so I would first make sure every particle of dust and loose crud was blown off the surface. Then I would take a many-times laundered scrap of tee-shirt, lightly moisten with spectrographic grade acetone and gently wipe the surface to get rid of any residual oily film. This would typically leave some streaks, which could then be removed by breathing on the surface and wiping gently with another clean scrap of tee-shirt. Never left a scratch (I would have heard about it if it did as the mirrors were something like $800). Today, I would get a good quality micro-fiber lens cleaning cloth and breath on the surface before wiping gently. Naturally, make certain any loose dust or other particles are blown off so you won't drag them across the surface.

[neil poulsen]

Thanks! I will give this a try.