Setup of my hardware went well (it all came back to me after the many months of not imaging). When I got to polar alignment I encountered the effects of my first brain fart... the telescope was not slewing to the right locations for my alignment stars. Oh yeah... it's 2010 and it's May, not October... it helps to enter the right date into the system! Because of my limited horizon and expectations, I did only a one-star alignment on Mizar and did my focusing there too. CCDSoft connected to the camera just fine and I didn't have much trouble using it. I've heard of people not liking the focusing tools, but they seemed to work well for me (though I wasn't controlling an auto-focuser or trying to control the mount).
I initially tried to go to M81 (Bode's galaxy), but didn't find it in the field of view (FOV). The image I took was extremely noisy (light pollution). I decided to try another object, so moved to M51 (Whirlpool galaxy) and this time I met with success (higher in the sky with less light pollution and closer to my alignment star). I decided to just take short exposures without auto-guiding. I took one 30" exposure and then took 14 or 15 one minute exposures. All of the single images had pretty noisy backgrounds but they came out nice when added together.
I finished up and took flats with my DIY light box, using a range of exposures with 12 images per exposure. It was during this process (when I'd already turned off my mount) that I found that I had not seen the 'filter' window in CCDSoft and had taken all of my images to that point with the red filter (brain fart #2... but perhaps excusable because it was the first time I'd used the software). I took a few series of flats with the clear filter just for comparison and then wrapped up for the night.
When I did the summation of my images after tear-down, the background noise cleared up, but I did see artifacts that I'm pretty sure are the result of humidity based upon what I've read. This is what I had half-expected and feared might delay my imaging season a bit more. I have asked SBIG to send me a new desiccant pack and I'll have to open up the camera and do a replacement (and clean the CCD window). Whether I can get this done in time to take advantage of May's dark nights is questionable at this point.
The flats came out with all sorts of features. I did a median average of all images and applied them to my summed-up light frames and what I saw was that it didn't seem to introduce any artifacts but it did bring back the background noise. What I had missed was that I should have taken dark-frames for the flats and adjusted them before trying to apply them to my image of M51.
The clear-filter flats I took had a feature that was quite different from the red-filter flats... what appeared to be fringing effects on the right side of the image. I'm hoping this isn't the product of a flaw in my light box, but I'll need to do a bit more imaging and diagnostics to figure it out.
Given that I didn't expect to get any good images last night, it was a very good night of imaging because it brushed the cobwebs out of my mind and resulted in some great learning that will help me do better next time. I'm very happy I'm not discovering these things after having ventured a hundred miles away to take advantage of dark skies, as it would have been a big waste of time and money.
Fourteen minutes (14x1')of M51 without flat adjustments. Frost artifacts?
My first flat-frame image with the DIY lightbox. A lot of defects!
