Hi, I've been trying to get M76 for a few days now using OSC ASI533. I tried several exposures and with no filter & with Optolong L-eXtreme LPF filter. The problem is that every preliminary processing of the images showing a different structure than that I've seen online and in books. Other pictures show the M76 with a central disk and opaque periphery. My pictures are the opposite, opaque center and dense periphery.

Does someone have an explanation or can tell me what I'm doing wrong?

PS: Please excuse my pictures quality as I didn't complete my capture or processing yet...



300sec with Optolong L-eXtreme


60 sec with no filter



Sample from other APs


 

Your first image looks well out of focus - there are plenty of hot pixels that add confusion. The second image is also out of focus but looks fairly representative of what you might expect. If you were in focus you should find that the fainter details around the bright dumbell parts start to show up.