Celestron Evolution 9.25

[MarcelVS]

So i got my new telescope week ago tomorrow but so far not really a clear sky. So frustrated. Any members with the same telescope with any advice to give a newbie?

[D44bond]

Make sure its collimated. After i collimated mine it was amazing

[MarcelVS]

Ok, its been 20 years since i last used a telescope...how do i do that with this beast?

[D44bond]

If you dont know someone who knows his stuff maybe buy a laser collimator off ebay and go youtube

[that_guy]

no need for a collimator with a SCT. Defocus on a bright star and look for concentric circle donut. If the shadow of the secondary mirror is perfectly in centre, it's in collimation. If it's not, its out of collimation. Use two of the collimation screws loosening one tightening the other until it is a perfect donut shape.

[StuTodd]

Should be good but make one of these for 50c, works perfectly evert time!

http://alpha-lyrae.co.uk/2013/12/31/schmitt-cassegrain-collimation-made-easy-using-a-duncan-mask/

:)

[Ukastronomer]

You don't use a laser on a SCT

[Hemi]

Hi Marcel, I’ve had this scope for about 3yrs. It’s a great package. You’ll have many yrs of enjoyment. Don’t worry about collimating initially, just get used to scope and enjoy the views. SCT’s in my humble experience are pretty good at holding collimating and should be st least reasonable from factory....including shipping!! As mentioned already you don’t need a laser for SCTs.
Here are 2 great links

https://www.cloudynights.com/topic/623603-collimation-of-an-sct-from-scratch-a-photo-guide/

https://astromart.com/reviews-and-articles/reviews/beginners/show/eds-guide-to-sct-collimation

Hope they help

Best

Hemi

[The_bluester]

My first suggestion would be to buy a set of Bobs Knobs collimating screws for it. Whoever decided that it was a good idea to make you wave a sharp pointed object around the corrector plate in the dark to collimate was a twit.

Secondly it really is easy for the SCT, as noted above, defocus on a bright star (Make sure it is not a binary like Rigel, been there :rolleyes:) and see how close the diffraction circles and shadow of the secondary are to concentric within the image of the star. Then using the hand controller, move the star off to one side to find the direction which makes the star image look better, if you can move it far enough to get it looking all concentric in one step then good, adjust the collimating screws to bring the star back in toward the middle of the field of view (Which should bring the point where the star looks right closer to the middle of the FOV)

A couple of iterations of that and you should be pretty right, you can then try refining it by looking at the star under the highest magnification you have available, in focus you might be able to make out the airy disc which should be nicely centered on the image of the star and out of focus it just makes it more sensitive to collimation being right.

It can make the difference between an OK view and a really nice one.

[Wavytone]

Get the collimation spot on. This makes a YOOOGE difference. The rest is easy.

[astro744]

I would not attempt collimation until I've had a look through the 'scope to see what the images were like on many different nights to account for different seeing. You don't want to inadvertently take it out of collimation. However you should be able to test on an out of focus star that is precisely centred in the field of view on the first clear night provided the seeing isn't terrible. As for the collimation procedure first read the manual that came with the telescope. Most SCTs hold collimation from the factory very well but it is still good to check but not fiddle yet.