130907_4203 original, uncropped. This is how a 1032 second (17.2 minute) exposure at ISO 400 looks, straight out of the Olympus E-M5 with no processing beyond whatever the camera does internally and the automagic stretch done by Lightroom/Photoshop and other conventional image processing applications to match human vision.
Streaked stars are evident, particularly in the lower right quadrant. This is my first successful try at autoguiding using the Lodestar guide camera with PHD software control. Now to learn enough to tweak the guiding so images are not streaked.