The new Peltier fridge allows me to get to low temperatures even on a hot night. The air cooled P fridge could only attain -5C if ambient was at or below about 12C.
This of course meant summer targets were noisier than winter ones.
I chose NGC 3576 as there are a couple of dark dusty nebula in the field. These would show any residual noise better than brighter areas.
Canon 5DH, 100ED at f/7.65 and FL 765mm with Hutech #7887 FR/FF. Hutech LPR filter. FOV approx 3x2 degrees.
Exposures 20X(1m, 2m, 4m, 8m) at 1600ISO. Fridge at -5.0C. Usual HDR method. Ambient started off at 22C and dropped to 18C.
Large image 8.8MB
http://d1355990.i49.quadrahosting.co.../ngc3576nf.jpg
Bert