TV Test Pattern – by Lois S.
Tuning Signals
Patterned cards were once used in TV studios to calibrate video cameras so that they were aligned properly. These cards were two feet by three feet, and were usually hand drawn. Later, the images on the cards were etched on a metal plate and used to calibrate TVs. The oldest test card was created in 1937 and consisted of black “art bars” (artificial bars) on a white background.