Mars imaging help.

[Trevor]

Hi Guys
Having quite a few problems with imaging Mars, I am using a C11 and DMK mono firewire, the camera settings I have tried are brightness 0 to 20, gain all through the range but try and leave it on 0
Shutter speed from 1/30 upwards depending on frame rate but usually leave it on 1/30 @ 30 FPS. Codec Y800.
I am getting a very pronounced onion ring effect I have collimated the scope to the best of my ability, I used Polaris and defocused then got the black circle in the middle.
It still looks like the collimation is out.
Please see the image below, any ideas would be gratefully received.
Left picture at F/10 right hand side at F/20 with a barlow, 4x imagemate is even worse.

http://img.photobucket.com/albums/v1...s/marscomp.jpg

Regards Trev

[iceman (Mike)]

The left image looks fine to me? I don't see any evidence of onion rings?

The right image simply looks out of focus? What's the histogram while you're capturing?
Are you using any coloured or IR block/pass filters or is this straight unfiltered luminance?

[Trevor]

Hi Mike
Just using a UV/IR filter, as for the histogram I haven’t used that as I have no idea what it should look like before capture, any info regarding this would be very useful, I have looked on the net trying to find something about the histogram but to no avail.
Any tips on achieving a good focus?
It’s a steep learning curve but will keep persevering.
Trev