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View Full Version here: : 8" GSO RC & NEQ6 mount


Jfinis
28-12-2009, 02:16 PM
Hi All,
I've recently purchased new equiment eg. NEQ6 and 8" GSO RC
I've seen a few posts concerning the 8" GSO RC and was wondering if anybody ca give me some tips on the best way to start setting up the equipment.
So far I've installed the mount and the scope on a pier, carried out basic polar alignment, I'm using a Mallincam VSS live video camera attached to the RC, I think collimation is out on the RC as I'm seeing elongated stars, I realise that they could be caused by Polar Alignment although I see very little dift on objects, what is the best way to collimate the scope so I can discount this being the issue.
I've ordered a new focuser ie. 1 x Feather Touch® 2.0" Dia Dual Speed 1.5" DTT, Brake, CRing (FTF2015BCR) and 1 x Adapter 2.0" - 90x1mm Female Thread (fits Astro-Tech 6" and 8" Ritchey-Chrétien Telescopes) (A20-M90X1)
Am I going the correct path to get the best out of the RC???
Any suggestions greatly appreciated, I had Andrew Johansen over last night and he helped me quite a bit, but he suggested that I post and try to get some tips from the RC experts

Regards
Jim Finis

Wishing you All a Very Merry and Clear Sky Festive Season

Moon
29-12-2009, 12:30 AM
Jim,
congratulations on your purchase.
What is the exposure duration when you see elongated stars? At that focal length tracking needs to be pretty good to get round stars during long exposures. there is also field curvature for off axis stars. I use liveview on my dslr and a bahatinov mask to collimate my 8RC. its on my website somewhere http://deepspaceplace.com
I'll post the full url when i get back to civilisation..
James

Jfinis
29-12-2009, 09:52 AM
Hi James,
Thanks for the reply I think there's lots to do before I get nice round stars, I'll try some of your suggestions
Regards

Jim

pmrid
29-12-2009, 11:22 PM
Hi Jim,
I have an 8" GSO RC. From bitter experience, I feel obliged to caution you about attempting to collimate it unless you really know what you're doing. They are far more difficult to collimate than a newtonian, for example, and you really need to proceed with caution.
Before I got out my set of Allen Keys, I would investigate all other possible causes of elongated stars starting with alignment, tracking and guiding and focus.
Peter

gbeal
30-12-2009, 08:37 AM
Jim,
I have waited for a few of the more knowledge out there to pipe up, but feel I should also toss in some thoughts.
Your original post is a little skinny on details for me. Are you guiding or just tracking, and what exposure length are we talking with the results showing elongation.
I agree with Peter, sit tight with the collimation at this stage, at least until you can tell us without guessing that it is actually "out".
Collimation is something you will need to tackle sooner or later, but right now get the rest sorted. Guiding etc, then worry about the rest.
The upgrading of the focuser will make this scope really nice to use, believe me.
Gary