Thursday, 2 April 2009

Scope bother

I had been keeping my 12 inch in the shed. The scope was well covered over and the shed is dry as far as I could make out - I certainly wouldn't keep an expensive mirror in a damp environment - but when I got it out yesterday the mirror was in a disgusting state, covered in dust and something that looked suspiciously like mould. I was not pleased but, following instructions I found on Cloudy Nights forum I decided to wash it. Anyway, I got it cleaned up okay, although there are still marks on the mirror but these are such that they won't degrade the image. I have moved the scope back indoors, although my aunt doesn't really want it in the house. I could take the mirror in and out of the scope but it is a time consuming operation and a huge pain in the arse to do.

Since getting the scope, collimation with it has always been a bother. As far as I'm concerned, collimation holds no fears, it's a piece of cake, but I don't want to be doing it five times in one observing session. The mirror moves around too much in the cell and the things that hold it in place are set too far apart. Also, I can never get it collimated perfectly, there's always a cometary look to stars at high powers, which is no good. I am going to ask my friend who built it to makes some adjustments to it. I won't need the scope for the next few months as I am going to be away in SE Asia and Australia (hoping for some southern sky observing - a small sky atlas, a printout of the AL's Southern Sky Binocular Observing list and my binoculars are coming along).