This year marks the beginning of my journey with this hobby and after countless youtube videos it's pretty awesome to finally get to do it myself.
In my last attempts of imaging Andromeda, which took place in two separate nights (1st time stacking data from multiple nights) I noticed a pretty big reduction in noise, which is to be expected with more data. I've also calibrated with some dark and bias frames, no flats though. My excitment was dialed down though, as after a few stretches in Photoshop I noticed that there is a pretty noticeable and sharp difference in noise between what gets stretched and, what I suspect, doesn't. This is also the first time I've noticed these (let's call it) "artifacts", probably because most of what I've tried to image so far (Orion and Pleiades) has been quite noisy all around.
So, I've come to get some input on what might be the reason for this. Maybe some of you have experienced this before.
Thanks in advance!
Camera - Canon EOS 2000D
Scope - RedCat 51 250mm
Mount - IOptron Skyguider Pro