Every once in a while I get the funny idea that I should do a star trails shot. The results have been okay, but I've run into a problem that forces me to crop out the top corners of the frame.
That's a full frame of a star trails shot I took last summer in Quebec. It was my second time doing star trails, an 11-minute exposure (using long-exposure NR) with my D80 on the beach looking out over the lake. I was a bit perplexed by the shot, because I hadn't seen anything of the sort when I'd first shot star trails.
The second picture was taken the previous December with the D40, also an 11-minute exposure using long-exposure NR. After some searching around it seems as though I'm suffering from amp glow problems with the D80. I had considered that the ambient temperature may have been the culprit (25°C vs. -25°C) but I also ran into the problem (to a lesser extent) in December 2011 with my D80.
In the end I just crop out the corners when the amp glow gets too offensive, but it's something I need to keep in mind as I'm framing my shots.
I'm curious to hear if this problem is widespread, or if it varies a lot from camera to camera. Is it possible my D80 is just a lemon? I'm hauling a D70 around with me these days, so I'm a bit curious to get out in the country and see if its results are more like the D40 or the D80.