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View Full Version here: : Ya Gotta Collimate!


shaneaust
05-06-2006, 11:44 PM
This is advice for newbies, by a newbie:

No matter where you got your new scope, and no matter how carefully you handled it when using for the 1st time - check your collimation!

I bought a new 10" dobsonian a couple of months ago. Got it home, set it up, and got some reasonably good first light views.

Decided to bite the bullet, and checked the optics, using a home-made collimator I crafted (!) out of a 35 mm camera canister. Had a heck of a time finding a good site to guide me thru the process, in language I could understand, but finally did. I've attached the article.

Finally got everything reasonably lined up (ie - as best I could, given my lack of skill in this area). Took the scope out that night, and - WOW! The views were just awesome, far better than those first few uncollimated viewings! I was amazed at how much difference in sharpness and quality, simply by making very minor adjustments to my secondary.

So - it's a REAL good idea to collimate very very soon after acquiring a new scope. If you're uncertain on how to do it, check the Internet for related articles, or PM me. It can - and will - make a big difference in what and how you see objects in the sky.

Mick :hi:

ballaratdragons
06-06-2006, 12:09 AM
Good advice Mick. It is worth checking collimation every session. Even if you believe you haven't lost colimation, check it.

This is probably the easiest site on the net for collimation (video) http://andysshotglass.com/Collimating.html


Bit slow for Dial-up folks.

rmcpb
06-06-2006, 08:41 AM
Like it or not collimation is an essential activity for all newtonian owners. It does not matter how large, fast or well handled your scope is the mirrors will need lining up or the scope will just not work properly. Its a bit like never tuning your car, it will still go in a sort of a fashion BUT not as well as it can.

I think all suppliers should include a Cheshire eyepiece with any new scope purchase so their product performs as well as it can straight up. This way they will get fewer complaints from their customers and we all know about the value of return customers and a good reputation in this small industry.

Anyway, you are right, Ya Gotta Collimate!

davidpretorius
06-06-2006, 09:42 AM
great straight forward article

I like this for beginners
http://www.schlatter.org/Dad/Astronomy/collimate.htm

and advanced star tests
http://legault.club.fr/collim.html

Kens spot on with that video, it is great

robagar
06-06-2006, 11:50 AM
... and don't believe telescope sellers when they say that their telescopes are collimated before delivery. Even if they are, they won't be after being trucked halfway across Australia!

davidpretorius
06-06-2006, 12:05 PM
or after you wash the mirror or attach a temperature sensor or kick the tube in frustration!

ving
06-06-2006, 01:23 PM
dont let a preshipping collimation be a sale point for buying a new scope cause in the end you are going to have to do it anyway (sure checking the scope before shipping is all good tho).

good on ya shane :D

Starkler
06-06-2006, 06:20 PM
Usually these factory collimation jobs are not spot on and they clamp everything down so tightly that they either gouge screw pits in the secondary holder or pinch the primary, meaning you have to release the tension and re-collimate anyway :shrug:

Conclusion, ya gotta collimate !

gaa_ian
06-06-2006, 07:35 PM
True Story, ya Gotta Colimate !
Great Video Ken, I have added that one to my collection.
Has anyone here used one of those laser collimators with the viewing screen ?
Mine does not operate like that !

astro_nutt
06-06-2006, 10:37 PM
Good one mick!!..the more you do..the more you perfect...it doesn't take long to check and adjust...but owning a Newtonian is a learning exercise which means you get to know every little part and the workings thereof. The great thing about this site is the abundance of experieced minds who are ready to share with you.

Geoff
30-06-2006, 08:08 AM
Hi from Geoff,
I turned up a lazer collimator and used a small lazer pointer in it which is adjustable with grub screws for centralizing. It has a target on a 45 degree angle so you can adjust the primary while standing at the back of the scope, and see the result. The lazer is the only way to go. very quick and easy.
Centre dot the primary with a stick on round piece of binder support. It is about 8 mm diam with a 3 mm hole. Check the internet on the best way to do this.
After using the Lazer, use an Auto collimator which is like an eyepiece with only a small hole about 3 mm which looks through a 3mm hole through the back of a mirror stuck inside. This thing gives a very fine final adjustment.
The auto collimator costs about $100 and has a good set of collimating instructions. I made my own for about $5.
I find that the Lazer on its own and a star test is good enough.
Cheers
Geoff

mickoking
30-06-2006, 01:39 PM
Very good advice :thumbsup: