Quote:
Originally Posted by cjpops
Re: collimating
Hi Mark, im actually too nervous to muck around with the mirrors, ill have to go to a stargazing event to see how others collimate their scope..
Still not sure whether to spend a bit extra on a laser collimator which is already calibrated out the factory (orion brand) - i might have to look up how people collimate to a star - sounds tricky
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Craig
Collimation is something you have a look at every time you assemble your telescope. If you want to see fine planetary detail its something to pay close attention to. 'Coma' on axis is the result of mis-collimation and it doesn't take much to smear out you planetary details .
Collimation on a star is the bit you can do after using a laser to mechanically check your collimation: it involves optical collimation - actually using your parabolic mirror on a star . It involves putting 3rd magnitude or fainter star in the center of your highest powered eyepiece that seeing will allow and studying the star disc as close to focus as possible where you can still see the secondary mirror shadow breaking out.
A simple iterative process of getting someone to move the correct collimation bolt, re-centering the star and reevaluating the concentricity of the rings. As you get closer you will need to bring the star closer and closer to focus , until you are just looking at the evenness of lighting in the rings. Once you learn the rules you'll find it takes a minute at most .Star testing is not done with the expanded star disc filling 1/3 the field of view as some people seem to do.
I would recommend the Astrosystems laser system which has a magnetised barlow lens attchment. This neat device works better than a standard laser as the lens attachment prevents slop in the focuser tube from effecting the quality of collimation.
I don't think I've ever seen a laser collimation job , that couldn't be tweaked further at high power on a star.
I wouldn't recommend getting more eyepieces until you have mastered collimation and been able to evaluate the quality of your optics.
Hope this helps.