I tried creating a stack of photos of the full supermoon using the RAW CR2 files from my Canon 70D and the resulting stack was brighter than any of the individual photos. I tried both median and average - no change. Since I was having similar problems with the focus stack, I'm hypothesizing that the problem is in reading the RAW files. I have not had a problem yet with a regular panorama or individual files. Once fixed, this looks to be a very useful feature.