Could you give me a cropped version of each? Basically, the image above, cropped like it is, but presented separately instead of as one overlaid image?

My first thought is that you're right and it has to do with lens distortion, but once I run a couple tests on it I'll have a better sense of things.

For those who haven't seen the film, look at Tim's version and reflect on the fact that Tim had never picked up a paint brush before starting the project. This was his first attempt at color, even. His handful of tests had been black and white.

For anyone with an interest in both art and imaging technology, this film is a must-see. It's just a fascinating--charming--look at a smart guy obsessed with solving a mystery.