I'm getting more facility using a long focal length reflector.....
I did my first collimation recently. I did't use an eyepiece. Instead, I used images to check the "donut hole" in the center of unfocused stars. I unfocused an image, and then zoomed in to the center of the image to see the star halos. I got what looks like a great result in the center. However, when I look at the star halos around the edges, the collimation looks off. The center looks great, but the edges look odd.
Is this a collimation issue or is this a camera tilt issue or is this a back focus issue?
For the record, I'm using an EdgeHD 9.25 at the native f/10. The camera is an ASI 6200MM and the images are taken through a ZWO luminance filter (which I know isn't the best).
Edited by dcm_guitar, 15 September 2021 - 12:59 PM.