Hello everyone. I recently got a Skywatcher Evostar 72ED scope with the 72ed dedicated flattener/reducer and use a ASI533MC Pro. I noticed the other night that my raw images had egg shaped stars but only on the bottom left and right. Both the field flattener and the camera both say to use 55mm of back focus which I have achieved, I think. not quiet sure where on the field flattener to measure but from the sensor to the end of the extensions is 55mm. Does anyone have any advice or things to check?
OPT had a article about egg shaped stars and according to their pictures my stars are all egg shaped point towards the center which they say the flattener it too close. Any help would be greatly appreciated!