About a week ago I was at the Microsoft campus in Redmond and had a chance to watch an action scene from the last Batman movie in one of their living room studios. The TV was pretty new and was showing the movie in interpolation mode or something. Subjectively, it looked like the Hobbit did. It didn't seem natural and kept pulling me out of enjoying the film. This comes with the comparison that I saw the same Batman movie in the theater this year and it looked much better at the slower frame rate.

I believe the optimal goal for fps is to mimic exactly what the human brain perceives with vision. Movies and/or video games should eventually seem like you're a spectator or looking through a window.

I just read through this page and it provides some good background, http://www.100fps.com/how_many_frames_can_humans_see.htm.

Basically, I think what was lacking in the Hobbit was a significant amount of motion blur. That's what we get naturally at a lower frame rate like 24fps. Simply pumping up the fps to 48 without adjusting for motion blur is what makes it feel weird. It definitely provides more visual detail, but that isn't optimal for the viewing experience.

I think an interesting experiment to do in the next few months will be to take the 48fps non-3D version of the Hobbit and add motion blur in certain test scenes while maintaining the higher frame rate. I hypothesize this will let us see more detail and make the images richer while appearing more natural to the brain.