Hi, last night I imaged for the first time using my new EdgeHD 8" but the results wasn't pleasing.
Sky Watcher EQ6-R + QHY PoleMaster
EdgeHD 8" + Celestron FR 0.7x
ZWO ASI1600MM Cool Pro
ZWO EFW + ZWO LRGB 36mm unmounted filters
ZWO ASI290MM + 80mm Guide Scope
Bahtinov Mask (I used Sirius star for focusing, I think now it's a bad choice considering it's apparent size)
My back focus was 106mm from the reducer to the sensor. ( the extra 1mm was recommended by ZWO when using filters)
everything is screw in type, so everything is tight together.
my guide RMS between 0.4px and 0.5px.
the next image was shot using the following settings:
1x1 binning (I think I should've used 2x2)
Unity Gain 139
the picture looks like a bit out of focus, but the shape of the stars is weird, is that how it supposed to look like if I'm out of focus?
I suspected that I need to collimate my SCT, but when I tested it using an artificial star it was a perfect Donut. so it shouldn't be that.
what do you think?