About Color Bars

Color bars are an electronically generated video signal that meet very strict specifications. Because the luma and chroma levels are standardized, you can use color bars passing through different components of a video system to see how each device is affecting the signal.

NTSC and PAL each have specific color bar standards, and even within NTSC and PAL there are several standards. When you evaluate color bars on a video scope, it is important to know which color bars standard you are measuring, or you may make improper adjustments. “SMPTE bars” is a commonly used standard.

When Should You Use Color Bars?

Analog devices always need to be calibrated and adjusted, even if only by minute degrees. This is because heat, age, noise, cable length, and many other factors subtly affect the voltage of an analog electronic video signal, which affects the brightness and color of the video image. Color bars provide a reference signal you can use to calibrate the output levels of an analog device.