Sunday, August 5, 2007

First light with the DSI Pro

Saturday night I headed out for a quick test of my new Meade DSI Pro. The weather finally cooperated on a weekend - first time in 3 months. Even after 10PM it was still pretty hot outside, and I had to wear long pants and a long-sleeved flannel shirt to keep the mosquito bites to a minimum. I was sweating, uncomfortable, and busy swatting the skeeters away from my face & ears, but I managed to capture a quick set of images. After taking a few test shots to tweak the focus, I set the long exposure mode to 60 seconds and let the software take it from there. Looking at the individual frames was not that impressive, but there was something there. Here's a single 60-second image of M27 - the Dumbbell Nebula:

I chose the option to save all raw images to FITS format. Since the DSI Pro has non-square pixels, the raw format file actually comes out "squished" horizontally to 508 pixels wide instead of the full format of 648 pixels wide. When using Envisage to do all the combining it automatically corrects the image scale. I am comfortable with ImagesPlus, so I just transformed the horizontal dimension in IP after alignment and stacking. I also took a few dark frames - here's one 60-second dark frame at around 80 degrees:

Having only 20 exposures I wasn't expecting much, especially after seeing the noisy single frames. But I was pleasantly surprised after a median combine and a quick DDP adjustment in ImagesPlus. The outer faint details in M27 were clearly evident in the resulting image. Next time I will try with my new LRGB filters. Overall I am very impressed with the DSI Pro and looking forward to much more imaging, weather permitting. Here's my result of 20 exposures at 60 seconds each:

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