[allan gould]

I was interested to see how the QHY10 would go with the GSO 10" RC scope and if there were to be any vignetting or difference in the flat field with a larger chip size. I only managed to get 4x5 min before the clouds rolled in on the 21st Dec and so the object was M42 as there are plenty of stars etc and I could compare the field with that of the 5" APO.
I must say that the image has no flats, darks bias etc and I'm quite pleased with the star roundness across the whole of the frame. No vignetting and a flat frame.
It looks like the QHY10 and the GSO 10" like each other and seems to do well from suburbia.
I had noticed previously with some of my images that one corner of an image would have slightly deformed stars which I eventually tracked down to that safety cut-in in the T to 2" adapter for the cameras. They just don't hold the camera in square without twisting it off centre. I got over this by ordering a new T to 2" adapter from Moonlight focusers that is just a straight, well machined 2" throat.
Fits the moonlight focuser perfectly without any off axis tilting.