High Dynamic Range

Dynamic range is the relation between the maximum amount of darkness and the maximum amount of lightness a video monitor can produce. On the majority of times the video monitor dynamic range is labeled as “contrast ratio” on its specs, even though this is technically wrong, since the real contrast ratio is measured using a standard image – a checkers pattern –, measuring the brightness difference between the center of the white squares to the center of the black squares. Contrast ratio is the difference between the maximum and the minimum brightness measured using this testing procedure.

The problem is that the human eye has a far higher dynamic range than any video monitor can produce. Standard CRT monitors have a dynamic range of 600:1, while good LCD monitors have a dynamic range of 500:1. Just to give you an idea of the problem, a scene showing the interior of a room with sunshine on the outside of the window has a dynamic range of approximately 100,000:1. That is why a picture of this scene isn’t as realistic as this scene “live”.

High Dynamic range or HDR is the name given to any video card and video monitor capable of producing a far higher dynamic range than current video cards and video monitors. The latest chips from both ATI and nVidia have high dynamic range features. On the video monitor business, a company called BrightSide (http://www.brightsidetech.com) release the world’s first HDR monitor, called DR35-P (which is a 37” monitor), which has a dynamic range up to 200,000:1 and a contrast ratio up to 25,000:1.