Join Date: Dec 2000
Location: Ottawa, Ontario, Canada
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I'm really not sure what Barco is saying here, or where they received their information. Perception is way more complicated than this, and follows something called a "photopic response curve" which is influenced by both frequency and the amount of light. In other words, certain frequencies cause retinal receptor cells (rods/cones) to fire more vigorously than other frequencies at a certain light intensity. Raise the intensity, and the frequencies left out of lower light levels may cause a more intense response. It's seriously really complicated. To say "the human eye has such-and-such contrast ratio" is incredibly unscientific and questionable.
The eye is an incredible machine, capable of firing off an impulse by a single photon hitting a receptor (rod/cone). Our brains filter this so that it still only takes 9 to 5 photons over about 100ms to be perceived! A person can clearly detect the light of a candle in total darkness from literally miles away. And these cells are continuously adaptable, and therefor constantly adjust their sensitivity (with the help of your brain as well). Brightness discrimination varies between individuals as well, especially since the brain is where the discrimination occurs regardless of source neural firing.
I mean good grief. What is the contrast ratio between rods/cones not firing at all, to those being bombarded by millions of photons per ms? Yeah, you get the picture.
Personally, Barco's claim as far as human eye contrast ratio sounds like marketing material aimed at the average and unquestioning population, and is not science. But hey, I could be wrong ;-)
[This message has been edited by Skyhawk (edited 05-19-2001).]