Here are the extreme upper and lower right corners from 2
of the Deerlick exposures stacked for the previous image.
These are both 5 minute, uncalibrated frames, and they
were taken only 30 minutes apart. It seems that the lower
right corner of the 7th exposure has stars that are elongated
vertically compared to the first image, but in the upper right
corner of the 7th exposure the stars actually look better than
in the first frame. I'm left unsure as to what would cause
parts of an image to vary like this.