Collimation Tools

Looking for some help. I am somewhat new to Astronomy and from different threads that I have read, Collimation is needed from time to time.... I have a Celestron CPC 8 scope and have no idea what I need, to do a Collimation.... So I decided to look at the Accessories list on Celestron web site and also Orino's web site and I cannot locate a (the) Collimation tool for a SCT.....

Can anyone guide me a bit as to where I can purchase one ? And perhaps let me know of what type to get also....

Thanks so much fo rthe help and advice..... It will be most appreciated....

Carl

Carl,

You don't need a special tool to collimate the Celestron 8" Schmidt Cass scopes. There are 3 screws located on the front of the secondary holder that do this. They may be covered by a plastic cover that should pop off. The process of actually collimating has been covered on several web sites.
http://ngc1514.com/Celestron/collimate.htm
http://legault.club.fr/collim.html

Many people like replacing the screws with Bob's Knobs. There is information on this site about collimation too: http://www.bobsknobs.com

Uncle Rod has instructions at:
http://skywatch.brainiac.com/sct-user/collimation.pdf

Another site that may provide some insight is: http://home.att.net/~starastronomy/Astrophotos/Articles/SCT-Collimation/sct-collimation.html

Brent Maynard has some nice shots of what you see during collimation at:
http://www.astronomy.the-maynards.us/collimation.htm

Unless you bang the scope around, it will usually hold collimation quite well. Final collimation tweaks can usually only take place under good steady seeing where the airy disk is visible clearly.
Some people use daylight collimation using a reflective object (Christmas ornament, Ball Bearing, telephone insulator located a good distance off to do collimation during the daytime and to avoid waiting for clear seeing.
Floyd Blue has some discussions in Equipment Talk about an artifical star he built to do a similar function.

Actual star test using the airy disk with a cooled down scope is still the absolute best.

Note that using a diagonal may not align you perfectly. If you always use a diagonal, then you may want to do it with it in, but do rotate it around to see if this changes the image. If so, you may want to look at getting the diagonal collimated or replaced.

Good luck and clear seeing,

Brian Risley

This is the only tool needed to collimate an SCT with great accuracy. That and a screwdriver and a few minutes time and your set. All for about $8.

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