Dear Everybody,
I have just started astrophotography and I have noticed some diffraction spikes in my images despite I use a Skywatcher 80ED. This is primarily present in corners, especially the upper right corner of the image (picture enclosed). Their placement was similar during two different occasions with different camera angles. I have nice round stars without spikes in the middle. My imaging train is the following: SW 80ED, Altair Lightwave 0.8x flattener, T2/Canon ring, Canos Eos 450D.
Could you please help me with what the problem might be. I have read that it can be pinched optics, but I am not really sure.
Thank you,
Gabor
diffraction.tif