[Zuts]

Hi Guys,

I am having trouble getting good focus on my SBIG, I am not used to what I am seeing and it is different from the DSLR. Firstly how far off is the focus on these two images?

M42, 3 by 240, 3 by 60, 3 by 30, 3 by 10 + darks
SBIG 2K @ - 15c, TV85

M50, 1 by 60 + darks
SBIG 2K @ - 15c, TV85

Secondly here is my procedure

With the SBIG in continuous focus mode and watching the sharpness graph

(1) Select a subrame with a bright star and adjust till maximum sharpness and star looks OK.
(2) Select a subrame with a bright star, put on hartman mask and adjust till all spikes converge.
(3) Remove mask and set to full frame. Adjust till dim stars 'pop' into view.

Any thoughts greatly appreciated

Thanks
Paul