The last week I've been busy capturing some object high above and far away.
In this image you see M31.
I used my Canon EOS 6D mark ii. With a Samyang (US: Rokinon) 135mm @ f2.8. Iso800
80 frames of 90 seconds.
20 bias, darks and flats.
Mount: SkyWatcher Star Adventurer.
I focused with a bahtinovmask and Backyard Eos.
But I have a question regarding flats: When I open the master flat created with Deepsky Stacker it is black. Only when I increase the brightness to a maximum I can see some vignetting. I thought flats would be greenish or yellow/White?