I saw a little segment of a show last night called "Unsealed: Alien Files - Aliens on the Moon" which showed the oblique image released here:http://lroc.sese.asu.edu/news/?archives/411-Tycho-Central-Peak-Spectacular!.html
. They adjusted the contrast and brightness of that image to get something like the attached image, claiming NASA was erasing part of the image to hide something.
Of course, the explanation is that the oblique image was a composite from the two NAC cameras on LRO. The demarcation line is exactly where the two images are joined. Examining the intensity level of the pixels in the bottom image "dark" shadow area (in the 8 bit tif images) is 2-3, while the value for upper image is 4-5. Why is the dark level in one camera different than the other? I think its due to the amount of light entering that camera. Wouldn't that affect the iris on the camera? I have seen many oblique LRO images where there were significant differences between the two cameras in terms of contrast.