JohnH
10-11-2015, 01:29 PM
Well the ST4K is new to me anyway so it rained for a week (sorry folks!), but cleared up last night, conditions were not so great, high cloud around and shooting into the south is towards Sydney from here. This is a stack of 16x5 min shots. I have had to resize to fit under the 200kb limit but am happy with this result, the camera is quite sensitive and clean.
One thing this shot does show is that I have one corner out of kilter,
I think it is collimation issue but would like a second opinion...the top left corner is the worst and has stars that are distorted like this -> \ ie elongated radially, it looks a bit like field curvature but the bottom corners look ok. Top right is also a bit off also showing a \ shape which for that corner is not radial.
So how should I proceed to debug this? I had no FR or filers in line so the scope was at its native F8 and the image scale is 0.75" per pixel.
One thing this shot does show is that I have one corner out of kilter,
I think it is collimation issue but would like a second opinion...the top left corner is the worst and has stars that are distorted like this -> \ ie elongated radially, it looks a bit like field curvature but the bottom corners look ok. Top right is also a bit off also showing a \ shape which for that corner is not radial.
So how should I proceed to debug this? I had no FR or filers in line so the scope was at its native F8 and the image scale is 0.75" per pixel.