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The Cygnus Rift as seen from Big Bear City on August 28. I used 4 30-second exposures at 17mm f/4, ISO 3200. Light pollution was reduced with a colorized dark frame (color sampled from a "black" portion of the original image, seen next.
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No, this was on a stationary tripod. I tried to take one 30 sec exposure every minute, but I had to wait for a couple of airliners and bright satellites to go through, so the sky moved a few degrees; enough to cause some lens distortion problems. I'll bring a tracker next time!
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I made a rough correction for sky motion by rotating each image (as a layer) around the estimated position of Polaris (using Photoshop), then tried to fix other small errors with the warp tool. None of this is necessary, of course, with accurate tracking.
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