Dynamic Contrast
Several manufacturers have introduced dynamic contrast controls to their monitors which are designed to improve black and white levels and contrast of the display on the fly, in certain conditions. It is supposed to help colours look more vivid and bright, text look sharper and enhance the extremes ends of the colour scale, making blacks deeper and whites brighter. This is achieved by adjusting the brightness of the backlighting rather than any adjustments at the matrix / panel level. The backlighting can be made less intensive in dark scenes, to make them even darker, and more intensive, up to the maximum, in bright scenes, to make them even brighter.
The official numbers for dynamic contrast are arrived at in the following manner: the level of white is measured at the maximum of backlight brightness and the level of black is measured at its minimum. So if the matrix has a specified contrast ratio of 1000:1 and the monitor’s electronics can automatically change the intensity of backlight brightness by 300%, the resulting dynamic contrast is 3000:1. Of course, the screen contrast – the ratio of white to black – is never higher than the monitor’s static specified contrast ratio at any given moment, but the level of black is not important for the eye in bright scenes and vice versa. That’s why the automatic brightness adjustment in movies is indeed helpful and creates an impression of a monitor with a greatly enhanced dynamic range.
The downside is that the brightness of the whole screen is changed at once. In scenes that contain both light and dark objects in equal measure, the monitor will just select some average brightness. Dynamic contrast doesn’t work well on dark scenes with a few small, but very bright objects (like a night street with lamp-posts) – the background is dark, and the monitor will lower brightness to a minimum, dimming the bright objects as a consequence. Ideally this kind of enhancement shouldn't be used in office work since it can prove distracting or problematic for colour work. However, movies and sometimes gaming can offer some impressive improvements thanks to such technologies.
