Daily Archives: Thursday, May 25, 2006

Here is a picture of a test pattern that used to be on TV after sign-off in the old days. For Mary D’s benefit she has to look at this! I quote form a web site: “Probably the most famous American B&W test pattern is the so-called “Indian Head” monoscope pattern. This pattern was originated by RCA in 1939; it was designed to be generated using a special tube called a monoscope, a CRT which had a metal plate target on which the pattern was printed. The black lines of the pattern would interrupt current flow as the pattern was scanned to provide the desired video output. These tubes could only handle black and white – no shades of gray hence they had to be simulated either with a halftone dot pattern or with patterns of fine lines…” From http://www.videouniversity.com/tvtestpa.htm In spite of the original technology and purpose of this … Continue reading →