After too much time with Google, I finally came up with the cause and the solution. The other night, though, I finally got frustrated enough to go searching for an answer. When others viewed the clips, however, they saw no such washout, so I was pretty sure I had a local problem - so I kept putting off trying to resolve it.
The left half of the image is the source AVI, and the right is the H.264 conversion. However, for most of the last year, I've been bothered by a horrendous amount of wash out in the converted video, as seen at right (click the image for a larger, high quality version in a new window). The size reductions are notable, dropping a near-two-minute clip from 186MB down to anywhere from 5MB to 12MB, depending on the quality settings I use.
I often use QuickTime Pro to convert video clips from my digital camera (which stores them as AVI files) into H.264-encoded clips, suitable for sharing on our family's blog site.
