TVL (Television Line)

On a test pattern consisting of closely spaced parallel lines, a TV line is either one black line or one white space that separates two adjacent black lines. The term TV Lines was introduced as an advertising gimmick to make TV, which has significantly less resolution than photographic film, seem to have more resolution than it does. Photographers, when they refer to lines of resolution on film, count only the black lines. Resolution expressed as TV lines (or as EIA) refers to the maximum number of them that can be side by side and still distinguishable, in the largest circle that in turn fits in the screen.