This is another example of an m31 image composed by 8×600 sec. L filter and 5×600 sec R, G and B filter, with 2×600 sec Dark frames

m31 - Takahashi sky90 apo - author: Franco Lanza

m31 - Takahashi sky90 apo - author: Franco Lanza

NGC2237 from tele1 skylive
M31 again: more exposures