Practically, NTSC is associated with unpleasant eye effects. This is not because of the reduced resolution, but because the original film material is shot at 24 frames per second and then converted to the corresponding standard—PAL/NTSC/SECAM:
Film video is usually transferred to PAL/SECAM (25 fps) by speeding up the video by approximately 4.2%. The effect of the speed is virtually invisible to most of us. Some, however, find it disturbing.
On the other hand, it is more difficult to convert NTSC. The individual lines that compose each frame are divided into two interlaced sets (the odd and even lines), which we call fields. A process called 3:2 pulldown then creates extra frames by repeating one field from a frame with the complementary field from the following frame. So some frames will contain fields from two successive frames in the film video, between which motion may have occurred. Again, this can be disturbing for a number of people.
Converting between the standards can be...