I’ve recently decided to give my Celestron Nexstar (Evolution) 6 OTA another go after a while sat on the shelf since I switched to a smaller refractor.
From a few test shots I managed to get a few nights ago, there seem to be a few issues that need looking into. Besides the obvious coma and vignetting which I can do very little about, there is a focus issue across the field with the stars on the right appearing significantly more distorted than on the left. Is this just collimation or is tilt potentially also an issue here?
I’ve attached a 300s test shot of M51 and a version cropped in on the centre of the image to hopefully clearly show the issues with the stars.
If needed the equipment/software I’m using with it is:
Canon EOS 600D (APS-C)
Celestron AVX Mount
Celestron f6.3 Reducer
T-adapter for SCT
Altair 250mm Guidescope + Altair GPCAM130
QHY Polemaster
NINA/PHD2
Any help would be greatly appreciated!
