Collimator for dob newbie

[Sardukar (Tim)]

First post

Ive decided to buy my first telescope, an 8 inch dobsonian. I was wondering if anyone could recommend me a good collimator? Ive watched some vids and read up on it, but not sure what to buy for collimation of the scope. Thanks in advance.

[Sarge (Rod)]

Tim,
Welcome to ISS.
8" dob is a very good starting scope, you will have many hours of enjoyment. But being as dob you will need to collimate regularly. It's not hard but does take patience and practice.

Two choices in the lower market - chessire or laser. Chessire are cheap and easy, but take a little practice to perfect, but will give good results. Must be done in daylight hours.

In lasers, an Orion Lasermate or similar brand is a good starting point and is very easy to use and learn with. Can be used day or night, but needs care in handling as cheap lasers are prone to loose their own collimation, but usually only a little, so still work pretty well.

Advanced collimation - cats eye, hotech or howie gatter - but they are expensive and can be difficult to use, so my advice and experience says, start with an easy and cheaper one till confident.

Good luck and clear skies.

Rod

[richardda1st (Richard)]

Yes welcome Tim.

I had the 1.25" orion lasermate, sloppy fit in the 1.25"/2" adaptor. Always gave a different result if you turn the lasermat around.

If you can, choose a 2" version with a barlow lens.

I'm totally satisfied with the accuracy of my 2" Astrosystem collimator, also it's reasonably priced. The 2" unit sits nicely in the focuser, no need to use the adapter.

If your scope is a one piece tube the lasermate with it's 45d window is very easy to use, but as I said, in my case it wasn't accurate.

Cheers
Richard

[barx1963 (Malcolm)]

Tim
The more expensive lasers etc are probably not necessary in an 8" as they are usually f/6 so a bit more forgiving. a basic laser is useful but it is no substitute for a proper collimation procedure. Try this link for the procedure I use. http://www.astro-baby.com/collimatio...on%20guide.htm
She doesn't use a laser, but it can be used as a final check. Once this procedure is done, I have found I only check with a laser most nights and every 2/3 months do a complete rn through to make sure all is OK.

Malcolm