[mldee (Mike)]

Finally, clear nights and temps still above zero!
Put the OCAL-collimated RC8 with imaging train on the AM5 with a 183mm binned 4 screwed onto the OAG housing.

First pics before any adjustments looked promising, although some donut variation across the image.

I have two questions:

1 - What is causing the variations in roundness
and
2- Which screws to tweak to improve roundness: Primary, secondary or image train adjusters?

Pic shows setup and initial image before any adjustments.
Thanks,