Coma corrector for Meade 10" SCT (non ACF)

[Spacer (Shar)]

Hello all,
I am planning to start with deep space imaging with the 10" non ACF sct on EQ6R. Can someone advise a coma corrector/reducer that actually works with it? I haven't heard many good reviews about Celestron and Meade 6.3.

Thanks.

[RyanJones]

Hi Shar,

You’re not after a coma corrector. The front glass on the SCT is a corrector plate. What you’re talking about is a focal reducer. I use the Meade 6.3 and I haven’t had any issues with it on my 9.25. Hope that clears things up.

Cheers

Ryan

[Dave882 (David)]

Lots of opinions out there- but here’s my experience with a 10” Meade LX50 (non-ACF). I use the celestron 0.63x reducer and as long as the spacing is correct you can get a pretty decent result.
Attached is an unprocessed live stack with the above setup with an asi294mc (4/3 sensor) at 105.3mm spacing (integrated darks and flats). Just few elongated stars in corners as I have approx 0.2mm tilt in my setup that I’m still trying to sort out but that’s another issue! It’s fairly easy to crop or process-out these flaws but the raw image shows the real result.

Focal reducers/correctors greater than 0.63x will cause more and more issues with distortions in the edges of a larger sensor so it becomes a bit of a balancing act and depends on what kind of result you’re after.

Hope that helps

[bojan]

Originally Posted by Dave882

...Attached is an unprocessed live stack with the above setup with an asi294mc (4/3 sensor) at 105.3mm spacing (integrated darks and flats). Just few elongated stars in corners...

Dave,

this is a very decent result.
I have other way around situation (C11 and Meade 0.63 reducer).. still trying to figure out the optimal distance (apparently my problem is field curvature).

[Dave882 (David)]

Yeah can be quite tricky to get the right spacing. I think most people probably get “close enough” and then get on with things.

Here’s a helpful diagram you may well have come across already that was posted on here a bit ago…

So many variables in play.
This was nothing compared to trying to get the Hyperstar spacing right!!
Vernier calipers are my friend…