M77

Hi,
Here is M77 from Friday.I didnt realize how small this one is until I started shooting it and saw the first images download,I need a bigger scope for stuff like this 8O
I shot this at F7 with my Tec and have noticed in all my images shot at prime focus what looks like vignetting or a giant hot spot in the center of my subs when I stretch hard.I dont get this when I shoot with the reducer at F5.6.
Does it make sense to have vignetting at f7 and not at F5.6? if not what would cause such a hot spot?

Anyway,here it is processed as good as I could get it,
LRGB,Luminance 1200x6 RGB 300x5 binned2x2
Images Plus for darks,stacking,RGB combine and DDP.Photoshop for all other processing.

Comments welcome,
Jason

Tec140 atF7
ST2000xm and CFW-8
G-11 on a pier

Attached Image:

Heres a 100% crop

Attached Image:

Nice detail in M77 Jason ! I can see the hot spot your talking about,I think...It seems to circle the galaxy right ? don't know what is causing this,could start making guesses but I bet you've alreay done that anyway.
Hopefully someone here will know what this is Jason so you can address the problem.

Jason,
Nice grab on that one. Really makes me want to go with a longer focal length and go after similar targets.
Larry

Thanks for your comment Jim.