Hello - I got AT6RC

[kimo]

Hi to all,

I GOT AT6RC , IT LOOKS GREAT BUT..?..?..?..

[ChaosKnight]

Dude, you just bought yourself a world of pain.

[orly_andico]

Focuser flop is a very common problem on all the GSO RC's.

Upgrading the focuser to a Moonlite or Feathertouch will help, but not completely eliminate the issues.

This is what you want to do:

http://www.cloudynights.com/ubbthreads/ ... er=3573309



OTOH, I think the "world of pain" comment is a bit overblown. Sure the focuser will hurt you, but you'll have bigger problems with tracking. Once your tracking is perfect, then you'll start worrying about the focuser.

[kimo]

Thanks for advices.
I collected few datas and still waiting for more collection for a perfect image. here i stacked some data just to show you. I think no problem with tracking or guiding and focusing. I used F/6.3 reducer but the spacing won't match as like C8 until some fine adjustment with CCD. very good contrast.

[orly_andico]

That looks pretty good... but it's because your small sensor camera is masking the defects.

1) RC's have a lot of coma, which an SCT reducer won't completely fix; but on-axis the coma will be small, and your camera chip is small enough

2) if your focuser is sagging, this will cause tilt of the sensor plane. Again tilt would be most obvious at the edges of a large sensor. On a small sensor.. not so much.

So all's well. For now..

I would be interested to see the result of 10- or 20-minute subs though. That's where flexure and such would rear their ugly heads.

[kimo]

I do lots of research on different scopes as I have it now before those are sold.
It’s very hard to decide which is one is best to use!
Here I took two images both are same exposure time.
Meade 8" SCT used F3.3 and AT6RC used F6.3. I know it won’t be same.
Meade 8" SCT showing coma at surroundings but AT6RC isn't.
First 8 inch SCT F/3.3 and AT6RC F/6.3: