Re: Recommended Maintainence for APM TMB 180

Taking apart the lens to clean between the elements is a pretty serious undertaking, and I doubt anyone would do it unless there was a significant problem.

I agree with Mark. There should be no reason to have the lens disassembled unless there is some significant damage to the lens cell or lens! In these triplets the spacing between the lenses and lens alignment is very critical and should only be done by an experienced optician who has access to specialized tools.

Certainly the lens may require a cleaning, typically this would be only the front. I use the method that used to be posted on the Astro-Physics web site - unscented plain klennex tissue, always one wipe then thrown away, moistened in water with a few drops of detergent followed by denatured alcohol followed by acetone. Works like a charm.

Since the design of most modern APO lens is aplanic, meaning they have no coma, they are very forgiving of collimation errors. Given the robustness of the CNC APM tubes, I would bet your scope is in perfect or near perfect collimation. You could always check it yourself with a cheshire and the cells push-pull screws.

I would not see a need to send it out for maintenance unless something is very wrong with it.

Philip

Mark Holden said:
Taking apart the lens to clean between the elements is a pretty serious undertaking, and I doubt anyone would do it unless there was a significant problem.