A crucial step in calibrating a display is to accurately adjust the display’s black level (Brightness control), which is critical to maximizing its dynamic range (luminance range from black to white) in the intended viewing environment. A display’s Brightness control adjusts the display’s black level. It sets the minimum amount of light the display produces at black signal levels.
Brightness adjustment is judged by visual evaluation of one of the multiple design PLUGE patterns available from different sources (Picture Line-Up Generating Equipment, per the BBC). The common ingredient of all these patterns is that they have blacker-than-black (below digital 16), black, and just-above-black test bars. The display’s black level is adjusted just low enough to visually match the levels of the black and the blacker-than-black test pattern bars.
Note: For accurate results, set the room lighting to duplicate the intended viewing environment for the selected viewing mode.
To Adjust Brightness (by visual test pattern evaluation):
- Display a Black Level test pattern.
- First, increase the display’s Brightness control enough to be able to see all the dark picture levels in the test pattern.
- Then, reduce the Brightness control just enough to make the two darkest parts of the pattern blend together.
- (For patterns with numbered dark bars, make the 1-16 numbered bars as dark as the background, with the number 17 bar just barely visible.)
If in doubt between two Brightness control settings, select the lower of the two settings. The brightness control has a significant effect on shadow detail. Be sure that the black level is set low enough to maximize the picture contrast, but not so low that dark grays are crushed to black and shadow detail is lost.
NOTE: If multiple points of grayscale/gamma are adjusted (i.e. 10-point grayscale), the Brightness/black level should not be readjusted after grayscale/gamma.