Hi Greg - First of all thanks for your prompt response. I'm new to CCD imaging so I apologise in advance.
I've linked the FITS file for Dark frame which is a 300sec exposure at -20 taken using SIPS software as well as a 0.2sec bias frame taken at -20 in the below link.
https://drive.google.com/drive/folde...hJ?usp=sharing
Unfortunately, I do not yet have a flat field generator so I did not have any flat field shots. I also do not have another scope to test on :/
I didnt even consider light pollution; I have been shooting all images at South - South West at 40deg above horizon from the backyard so that could be a possibility.
I'm using a SVQ100 so the image is inverted which could explain why the light gradient is on top of the image.
Just to confirm if this was a CCD issue we should see the same glow in the darks and bias am I right?