Re: [ATM] Ghosts in the Coulter

["John Murray" <onslow@cyberone.com.au>]

Morning All,
	I had a very similar problems several years ago when learning to
collimate properly. A beautiful ghost of Jupiter that refused to go away.
Much consulting with the list. Advice at various times was optics pinching,
(main and / or secondary) Cells warping, poor collimation focussers offset
etc etc. After several months of persisting I finally got rid of it. It was
due to collimation issues. The laser is only as good as the centring of the
dots AND the laser being trued in vee blocks. I had tried cheshires but as I
got close I found it hard to tell the shape of the concentric circles due to
problems with the tube being crappy and out of round etc. This was while I
was still learning star testing. For that I find I need to be reasonably
collimated to start with. I now find all three tests equally useful. After
much convincing of myself for a long time that I KNEW the scope was
collimated I found it wasn't.

Cheers

John Murray
Whyalla
South Australia

>Temperature causing warping of mirrors/mounts?



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