[Keyframe]

I've read it in Cinefex long time ago, might be there is something online too. Douglas Trumbull did some sort of a controller experiment in front of a crowd with 70mm projection.

Which shot images have you seen played faster than 72 fps? I've seen one test played back at 120 fps, but it was in a camera r&d lab in germany. 72 fps is really more than enough. Consider that 3D projection actually projects 3 frames per each eye, so 3D@72fps would actually mean projector is churning out 432 frames each second. Or you're talking about games, which is another thing entirely since input is a part of experience too. In that case, I agree.

[PaperclipTaken]

They project each frame 3 times so that your eye can't pick up flicker from the light going on and off. I'd imagine that at the full 72fps it would not be necessary to flash each frame 3 times.

Finding a 'framerate' for the eye is difficult. Under certain conditions, 60hz (think florescent lighting) can be enough that your eyes won't notice a flicker. (your eyes hold a residual for some period of time, and you never see the darkenss). But if you are flashing a series of super-crisp photos, your eye is much more likely to pick up on stuttering because each photo has just as much light.

And then, if you have some action sequence in a movie where parts of the scene are really bright and fast-motion, and others are dim, the minimum amount of frames per second you need to create a 'perfect' experience for the eye is anybodies guess. It would probably also make a difference if you were a person used to looking for flaws in a picture, vs a person who is just trying to enjoy a movie and doesn't know anything technical about framerates, etc.

Regardless, all forms of currently available cinema have framerates with room for improvement.