Interlace scanning allows only half the lines to be transmitted and presented at any given moment. A 1080i HDTV signal transmits and displays only 540 lines per 60th of a second. 480i NTSC transmits and displays only 240 lines per 60th of a second. Motion in the image makes the fields noticeable. Interlaced images have motion artifacts when two fields don't match to create the right frame, often the case with film-based material.
Larger numbers mean more resistance.
Measured in ohms. The image is shaped like a trapezoid, rather than a rectangle. A motion picture projector.