Thank you both for the feedback so far, it's already been very useful as it is starting to confirm my initial thoughts of poor tracking and focus not being perfect
I am using the standard motorised mount that comes with the Celestron C5 - very much not in the HEQ5 class! Also not using polar alignment and using the standard SkyAlign that comes with Celestron software - would polar alignment be more accurate despite the mount?
I have also attached a .jpg of one of the better light frames
With regards to tracking and the standard mount I am using, would reducing exposure times be useful or looking at a better quality mount a better option?
Thanks,
Will