NTSC TV Test Pattern

The test card usually has a set of line-up patterns to enable television cameras and receivers to be adjusted to show the picture correctly. (Compare with SMPTE color bars.) Most modern test cards include a set of calibrated color bars which will produce a characteristic pattern of "dot landings" on a vectorscope, allowing chroma and tint to be precisely adjusted between generations of videotape or network feeds. SMPTE bars—and several other test cards—include analog black (a flat waveform at 7.5 IRE, or the NTSC setup level), full white (100IRE), and a "sub-black", or "blacker-than-black" (at 0 IRE), which represents the lowest low-frequency transmission voltage permissible in NTSC broadcasts (though the negative excursions of the colourburst signal may go below 0 IRE). Between the colour bars and proper adjustment of brightness and contrast controls to the limits of perception of the first sub-black bar, an analogue receiver (or other equipment such as VTRs) can be adjusted to provide impressive fidelity.

Category:

Entertainment

Tags:

• TV
• Test
• Patterns
• Commercials
• Noise
• Infomercials

[k9builder]

I remember when I would see this at the end of the broadcast day. I can't believe that I now live in an age where few even seem to remember these.

[8bityoshi]

anyone else find it funny that one of these test things was spongebob's secret channel in the episode about patrick's secret box?

[jjlwis]

good description on the side bar!

thanks for putting up the bars...