thought the hobbit was filmed at 48 fps because of the 3D filming technique it used required that to get the lighting right
The drawback with the Hobbit and it being filmed at 48 is that for the majority of people it'll look horrible
in 3D cinemas that can show 48 FPS (basically all), it'll look fine. IF they filmed it in 2x24 fps.
If they also filmed 2x24, then it'll also look fine in 2D cinemas as they can just show the left or right eye frames at 24. in which case the movie was actually shot at 24.
HOWEVER, IF the movie was actually shot at real 48 fps. it'll look horrible at most cinemas without special 48fps equipment.
their alternatives are to either
1: show every second frame.
Drawback: since it's shot at 48 fps, the images are much sharper. with less motion blur, and since you're cutting every second frame you get a gap in the movement added to the extra sharp images you get jerky movement, while the eyes can't "see" it, it's noticeable because the eyes will still see everything jumping form place to place since there's no motion blur in between and there's a gap in the movement, effectively giving it the effect of a low fps cartoon or a game at 30 fps as opposed to 60 where the eye can fill in the blanks. it will in fact look worse than a 24 fps movie
2: in order to avoid the "jerky" appearance of cutting out every second frame, they can instead blend two and two frames into one frame. so frame 1 and 2 becomes frame 1 and frames 3 and 4 becomes frame 2. using either simple blend or more advanced morph techniques.
Advantage: smoother look
Drawback: you're merging two frames with two different steps of motion blur, show after each other in sequence they would look good, merged together they get weird and they don't really merge and you end up with a horrible PQ result.