2012-04-28
post/21952379026
photo 03:29:41
EIA Linearity Chart, 1961. An explanation from the no-frills technical links page:
In the 1970s, if your color cameras had registration problems, the ball chart would show them to you. You see, the cameras had separate tubes for red, green and blue (RGB). After the RGB signals go through the NTSC encoder, and sync is added, it is then called composite video. If you point your Norelco PC-70 at this chart and the black circles have rainbows around the edges, you need to twist some knobs to get the red, green and blue pictures to coincide.
