Another collimation question.

[srv]

Just got my 10" GSO Dob
and don't yet have any collimation tools.

I made an eyepiece using the 35mm canister trick
and I can only see two clips on the primary mirror.
I'm assuming my collimation is out, but querying which
mirror is out.
I've read lots of articles etc, from what I can tell
the secondary mirror is out.
Would this be correct ??

I've ordered a laser and a cheshire today so
that should help when it gets here.

Thanks for the link to http://www.andysshotglass.com/Collimating.html
it's one of the best I've seen.

I was tossing up the idea of buying the catseye tools, but they seemed to be a bit expensive ( US - AU $ conversion + post)
Are they overkill for a beginner ???
I also wasn't keen on removing the spot on my mirror, to put the catseye on it, or do most people put the catseye over the existing one ??

I also had the same problem as trying to focus the viewer, thanks to another thread here, I found out about the locking ring on it. So that's at least one thing sorted.
Anyone have tips on how to align the viewer ??
I assume you just align it with a known point to match the OTA view.
Wondering if the purchase of a Telrad would be worth looking at.

Thanks.

Matt.
(newbie)

[erick]

Hi Matt and :welcome:

No you don't need the Catseye tools (Edit: Yet! Maybe one day?). If you really want to spend more money than you have, then in time you might consider getting a purpose-built barlowed laser in from overseas:-

http://www.iceinspace.com.au/forum/showthread.php?t=24955

Now, have you done lots of reading in addition to Andysshotglass, eg:-

http://www.iceinspace.com.au/index.php?id=63,390,0,0,1,0

In the latest Australian Sky & Telescope magazine (in the newsagent now) there is a good article on finderscopes including tips on aligning them.

Eric :)

[hickny]

Matt,
I saw somewhere that to check the alignment of the secondary mirror it is a good idea to cover the mirror with a piece of paper roughly the size of the mirror. When you look through the view finder you can then see if the mirror is correctly aligned. So simple can't imagine why it wasn't mentioned earlier.
Good luck.
Peter

[GrahamL]

hi matt :)

great scope :thumbsup: a telrad is a very handy accessery .
nothing drastic sounding there .. your primary tilt sounds like its a little way off .. try it as is and see what you think :)