Quote:
Originally Posted by Blackant
Wow, thanks everyone for the welcome, advice and the quick replies 
Unfortunately money is going to probably be an factor, but having said that both the Cat's eye ones and the Orion Collimating eyepiece are both within my budget.
With the cat's eye cheshire kits, are these the one's people meant?
http://www.catseyecollimation.com/cekit1s.jpg
I did a fair bit of reading about what you can use before posting, but to be honest I was a bit bamboozled by all the information 
This has helped a lot, ta.
Kind regards
Ant |
Ok, get a small laser collimator for the field (approx $150). Reason: when you're in the dark you want something quick and painless to "finish off" your collimation and you won't see any mirror central spot in the dark. The cheshire won't be practical.
At home in daylight it's a different story. You can make a sight tube (PVC pipe + fish line) with a reticule to center the secondary and buy a cheap cheshire (approx $50) to do the primary rough alignment. Later on invest in the CatEye tool kit. ($$)
If you ever get a very big aperture dobsonian a holographic laser collimator (approx. $300) is the way to go. It projects a grid and a central dot but you need to see the reflection into the secondary from the front of the tube so it needs to be pretty wide (might not work on your 8" DOB). For a big DOB that's the quickest way to align and collimate on the field. Literally 1 minute or so.
You also have to make sure your laser collimator is itself "collimated". If you stick it in a lathe or rotate it and project the dot on a wall at let's say 2-3m the dot should "reasonably" stay centered and not circle around. They rarely come aligned out of the box. Worth checking because then you'll really screw up your scope collimation if you use it and do more bad than good. Once your laser collimator is set put it in a safe place and don't drop it or it'll go out again.
Have fun.