Hi,
This image is from my 8" Skywatcher Quattro Newtonian (just a few frames to illustrate the problem). The newt is relatively new to me but I have had a couple of previous images from it without issue. I just put the newt back on after using my refractor for a while and got this mess.
The stars - particularly bright ones - show trails that i initially thought was tracking but PHD2 says tracking is around 0.7" and the trails do not appear uniform across the image. Have since checked tilt and collimation but both appear good. Notably the aberration diminishes and then disappears as the scope tilts to the zenith.
I don't even know whether this is a mount or optical issue - hopefully somebody can help me out.
