Well, it's been a while since my last attempt at astrophotography as my old ThinkPad gave up the ghost at about the same time as I sold my 40D in favour of a 5D Mark II. The final nail in the coffin of my astrophotography was the realisation that I'd also need a new light pollution suppression filter as the one I had used on the 40D (and the 400D before that) was way undersized to be usable on the full-frame 5D2.
Anyway, I recently dipped a toe into the world of Apple and got a MacBook Air which can control my 5D2 courtesy of Canon's EOS Utility software. I also invested in a 72mm IDAS LPS filter so the only thing stopping me from getting out in the cold night air was, I'm sorry to say, lethargy coupled with some inclement weather.
Last night I tried to put that right but the observing conditions were, to say the least, unfavourable with a thin high level cirrus drifting in and out of the field of view making it very difficult to predict which shots could be exposed as "lights" and which as "darks". For more on "lights", "darks" and much else you can check out the IRIS tutorial here
In the end I captured seven "lights", plenty of darks (all exposures were 120 seconds) and, together with some bias and flat frames made earlier, I set to work with the free IRIS
software. Seeing was so poor when I set up the telescope that I couldn't see Polaris in the mounting's polar finder so I did the best I could. Not good enough as it turned out as each star was elongated into a trail several pixels long.
As a result of all of this the final image is not pretty and is very much a rescue effort which owes more to post-processing finagles than scientific accuracy. The image is in the vicinity of Auriga
and was captured with my 5D2 plus EF 85mm f/1.2L USM wide open at f/1.2, with the camera piggybacked on top of the telescope and so using the mounting to track the stars. IRIS did the initial processing and PhotoShop was used to finish it off.
I'd hoped to capture more of the nebulosity in the region but ineptitude on my part coupled with the conditions on the night have served to remind me how hard one has to work to get good results.