M42 last night

Jeez Paul, wish I could get an image like that after only 3 sessions! Took me yonks to get an image like that.

I used to use a 7D on an F5 Newt and eventually found the following; could be different on the 5D though. BTW the ha response on these two cameras is quite good even with the stock IR filter.

1/ Setting the timed exposure to 2s instead of the default 10s enabled mirror-lockup so that got rid of any mirror slap. I found this completely by accident.

2/ A coma corrector worked great to get stars at the edge of the field to pinpoints. Mind you, I always ended up cropping the image anyway, due to the large field of view so this ended up not being too important.

3/ You'll get great results @ ISO 1600 and just stack a few more shots.

BTW, I hate collimation but had to do it and found the Flash tutorials from this site invaluable. It even made it clear for me
www.andysshotglass.com/articles.html

Trev

On my recent image of M42 I combined 6-300sec, 16-210sec,15-30sec and 15-15sec subs. All shot at ISO 800 in raw format with a modified Canon 350D. No darks, bias or flats were taken. The 30sec and 15sec images were masked into the longer exposures using Images Plus, after being registered with Registar.

Better then any images of mine after only the third session. Time in the saddle is the best learning experience.Also, don't be afraid to try something different when processing. You just may be surprise with the results.

Nice image, the lads above pretty much said what I was thinking.
Keep up the good work.