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Collimation query

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Hi all,

So I've recently purchased my first telescope after toying with the idea for about a year. Got myself a skywatcher explorer 130p. Seemed a decent price not too cheap but not too expensive - plus a nod from the BBC's sky at night review on said scope was particularly good and sealed the deal.

Anyway, I've started collimating it for the first time, I've got the spot lined up nicely but the cross-hairs aren't aligned. My -possibly silly - question is do the cross-hairs also need to be aligned or just the spot? I'm thinking they do, and so I was wondering if anyone here can explain how to do it, please?

Do I turn the screw on the center of the spider to move the secondary mirror?

I think I'm more looking for conformation that I'm not going to [removed word] up my new scope if I do



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Hi there.......avondale. If the scope is new, it wont necessarily need collimating out of the box, however, if you feel the need, carry on. There are many web pages concerning collimation, and once mastered, its an easy task, however, trying to describe without us seeing your results and adjustments is a tad difficult. That said, many have learnt from this great article. http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

You should  separate the image reflections, it helps,  in order to centralise the  secondary mirror, before aligning the primary.

Be careful you don't confuse the  'cross-hairs' (if fitted to your collimation tool)  with the cross-hairs that are the result of looking at the 'spider-vane'  that supports the secondary mirror.

Just read, and re-read that guide.

Don't assume its easy until mastered, then you'll wonder what the fuss was about? :laugh:

Edited by Charic
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Best advice would have been to try it first and see how things looked.

Two thoughts come to mind, if it ain't bust don't fix it, and, if the secondary is one side and the main the other but the image is perfect do you really care? :eek: :eek: :eek:

You are now likely to need a collimator, about £25-30 to find out the present situation, if you do not already have one.

Collimation is actually mechanical alignment of the components.

This seems to get forgotten many times.

Edited by ronin
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Having recently gone down a similar road (new to the sport, new telescope, collimation!), in retrospect I'd heed Ronin's advice. It's not that you can't collimate, and there are several good guides on the interwebs: http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm is a frequently referenced one.

It's that beyond getting the primary lined up (spot centered), if the view is satisfying then your time might be better spent learning the ropes of finding targets and observing, rather than tinkering with the secondary. I played with mine early on and spent three months feeling stressed because it was more out of line than when I started and I couldn't figure out how to improve it. Eventually I wrapped my head around what I was seeing, applied the plastic washer technique (mandatory) and got it back to a decent alignment. On the plus side, I learned a lot about collimation. On the minus side, I probably could've been learning something else with more reward and less stress.

If you're mechanically inclined and get off on tinkering with hardware, go for it, but if your goal is to learn the skies and see cool stuff, further collimation can probably wait.

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