hi Troy.
Thanks for your interest. As far as I can tell, this effect is widespread in lunar images taken in good seeing and with low angle illumination. There is often that little white line tracing around the boundary inside the dark zone of high contrast craters. A quick look around found a few examples from a variety of operators, cameras, optics etc (see especially the craters in the upper left of the second listed image):
http://www.damianpeach.com/images/lunar0709/baco_2007_05_23dp.jpg
http://www.damianpeach.com/images/lunar0709/beaumont_2007_05_22dp.jpg
http://the-moon.wikispaces.com/LPOD+May+28%2C+2008
http://the-moon.wikispaces.com/LPOD+Apr+15%2C+2008
http://lpod.wikispaces.com/May+13%2C+2011
All of my images were taken at 60hz with a DMK618, which does not have the dreaded 60hz double image artefact - I also have an 098 based DMK camera, but that
does have the artefact and I don't use it much anymore for that reason.
The simulation was intended to show that the same little white line can be produced by sharpening a synthetic image that started out life with an abrupt high contrast edge and then was blurred by an Airy pattern. I don't think that the effect has anything to do with the camera - the simulation was prepared without using one and suggests that the artefact is an unavoidable outcome of the optics PSF and sharpening combination. The simulation also shows the more subtle dark boundary echo that can be formed in the bright zones of such an image and this effect can also be seen in the real images.
There are a couple of ways to mitigate the "white line" effect. One is to use "curves" to black out the darker areas of an image and many published lunar images look to have been processed this way - I guess it would also be fairly easy to manually brush out the effect in an important image. The other is to image with more direct lighting, so that there are no extreme contrast regions in the image - many lunar imagers do this.
regards Ray