Field curvature of Meade ACF's

[aarong]

Hi all,

I'm trying to work out why I may have excessive field curvature (60-100% as measured by ccd inspector) in my photos from my 8" lx90 ACF f/10 and QSI 683WGS combination, but firstly, what have others measured from their set-ups using a Meade ACF f/10? I'm not sure what I should be expecting.

I noticed it why collecting subs for this image (http://www.iceinspace.com.au/forum/showthread.php?t=136397). The image has been cropped a little, but you can still see it.

I have also posted the same question in the lx90 yahoo user group.

Thanks,
Aaron

[Atmos]

I have some old images that I have taken with my full frame (36x24) DSLR through my 10" F/10, I'll run some of those through CCDInspector tonight.

[aarong]

Awesome! Thanks for doing that.

Aaron

[aarong]

I should also mention that I use a 2" nosepiece with the QSI. I have attached an example of the upper end of the field curvature I have measured and a sub.

Any measurements from others with similar set-ups or with an lx90 would be interesting and help to work out what field curvature I should aim for.

Cheers,
Aaron

[jenchris]

Looking at the sub you posted is nothing like the subs I get with my acf8.
I can see coma in the edge stars and the ones in the middle are oval.
This tuc47 is one I took in 2011 when I was just starting.
It's a single frame, unguided.
My stars are pretty much round to the edge of you ignore the lack of finesse in other areas

[aarong]

Thanks for this. Interesting...
What camera did you use?