Difference between NTSC and other formats
The most important difference is found in the frame rate, i.e. the frames per second (FPS). In America the sockets for electricity have a 60 Hertz frequency, in Germany, however, the frequency is only 50 Hertz. This dictates how often a picture change takes place on the screen and thus also how many pictures are displayed per second. 1 Hertz stands for one image change per second. The PAL format and SECAM both transmit at 25 FPS, with each picture being shown twice and reaching exactly 50 picture changes. NTSC, on the other hand, transmits with 29.97 FPS, which does not result in exactly 60 image changes.
