Went to DAS dark site and finally got stack of M33 and NGC253. Used setup in sig with IR filter. Seeing wasn't great as could only pickup one central star in M57. Playing with stack size and exposure time I found; Stacks over 1000 at 2.5sec exposures lead to excessive green, while stacks over 1000 at 10sec exposure lead too lose of detail. Loss of detail was due to mediocre seeing.
M33 10s 988 frames
NGC253 10sec 1050 frames
M1 10sec 494 frames
Horsehead Nebula 10sec 702 frames
NGC2024 - 10sec 385 frames - lack of detail obvious, seeing not so great
Edited by CharlesC, 26 September 2016 - 11:48 AM.