Strum Drum Messages: 229 Registered: November 2017
Master
on TVs actually serve a purpose, as I just learned. It is a test pattern for calibration purposes. Engineers actually still use it today in order to adjust the color schemes so that each television that is manufactured will align with the standard. That's pretty nifty! I rarely saw them as a kid. I grew up with 24-7 television, so the whole nightly sign off thing wasn't part of my experience.
Wayne Parham Messages: 18793 Registered: January 2001
Illuminati (33rd Degree)
Before the SMPTE color bars, there was another common test pattern, as shown below. It was used to check things like the linearity of the sweep, overall size, contrast and frequency response. Poor frequency response made lines fuzzy rather than having sharp edges and poor linearity made them spaced closer or further apart on some sections of the screen than others.
Cool! I love little tidbits like these. I always thought the color bars were part of the reel and were meant to show off the magic of color television. I had no idea that they actually have a name, so thank Wayne for sharing that one. I'm surprised that there's a color calibration standard among all televisions though, because it certainly doesn't look that way to me.
johnnycamp5 Messages: 354 Registered: June 2015 Location: NJ
Grand Master
I don't remember the earlier test pattern that came before the color bars (Waynes example) but I'm quite offended at the "Indians head" at the top.......
gofar99 Messages: 1951 Registered: May 2010 Location: Southern Arizona
Illuminati (5th Degree)
Hi, I not only remember them I used them. At one time as a portable unit to field test color TVs I had a special cartridge for an Atari 2600 that was designed to produce the various patterns needed. I probably still have it. It might be interesting to see how well some of the newer TVs are actually calibrated for color balance and purity. The alignment (horizontal and vertical lines) should be perfect as the display is a digital array.
I remember seeing these color bars, but I only learned now that it has a purpose. I've always thought that there was something wrong with the channel when those things would flash out.