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Old 14-05-2010, 10:54 PM
ausastronomer (John Bambury)
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Join Date: Mar 2005
Location: Shoalhaven Heads, NSW
Posts: 2,620
Quote:
Originally Posted by mental4astro View Post
I use both a laser collimator and a 'cheshire' style eyepiece.

I use the cheshire first to sort out the secondary's situation first, and then the laser for the primary. The laser alone won't deal with secondary mirror's needs adequately.
This is 100% correct.

Importantly even if your laser itself is collimated it can't handle the secondary mirror positioning from scratch. Further, you can adjust the tilt of the mirrors to have the laser striking back on its exit point making the telescope appear collimated, when in fact it is not even close.

The Tectron Tools are excellent (if you can still buy them), as is the cat's Eye collimating system. The Orion combination tool is a good cheaper option, but can be a bit disconcerting for a beginner to use. The more expensive systems like Tectron and Catseye, which use a separate sight tube, cheshire and autocollimator, are easier for an inexperienced person to learn what's going on.

Cheers,
John B
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