Taken just before midnight on St. Patrick's Day. Seeing was not quite 3/5 as predicted by the CSC. I used a 1.8x barlow and 2.25" extension to produce this image, however, I pushed the barlow into the focuser all the way thinking it would be more stable. As it turns out, the extension magnification is increased by extending both before and after the barlow at least for this setup. The result was a smaller image closer to f27 than f30. Next time I will maximize the length on each side to capture the largest possible size. Using a strip of tape I blocked half the flow from 1 of my cooling fans, restricting the intake to approx 5cfm which I left on during the imaging session. The rear mirror temp stayed within +/-0.2degC of ambient during the 2.5hrs period, even as the temperatures dropped 1 degC per hour. Too bad the seeing did not enable me to take advantage of the excellent thermal condition.
I stacked 1200 frames of L (1/30s), 800 R,G (1/15s), & 800 B (1/8s).