Hitachi Boasts 8,000,000:1 Contrast Ratio

[welwynnick]

Originally Posted by HDTV1080P

Some one needs to come up with a standard that all the manufactories agree to when measuring contrast ratio.

There are standards, but people don't always say what standard they are referring to. In simple terms, there are probably four different types of contrast:

1) Maximum On/Off contrast, say 4000:1
2) Calibrated On/Off contrast, say 2000:1
3) Maximum ANSI contrast, say 200:1
4) Calibrated ANSI contrast, say 100:1

"Maximum" means every last drop of light and dark you can get, using any possible combination of settings at your disposal, and to hell with fidelity, colorimetry, greyscale, etc.

"Calibrated" means fixed settings and linear brightness and colour response.

"On/off" (also called sequential or INTER-frame contrast) means the difference between the brightest possible bright frame and the darkest dark frame.

"ANSI" (a standardised type of simultaneous or INTRA-frame measurement) means the difference between the brightest and darkest part of the same image.

Manufacturers usually seem to quote the highest possible figure, without explaining what it is, and "independant" testers seem to quote the lowest, and often fail to explain that, too. The best manufacturers (Like InFocus) and testers (Like Cine4home) give you all the information, but sadly there aren't enough like that, hence the confusion.

There are some complications, such as with CRT and PDP displays, which only achieve max brightness and contrast with small areas of illumination, and with projectors, where contrast can depend on lens, zoom, and iris settings. So results really need to be qualified to be comparable.

While I have heard despicable urban legends about unscrupulous manufacturers who improved their measurements by turning their display OFF to achieve a better black, I wouldn't usually be too sceptical about some of the seemingly inflated recent claims. Contrast really should and could be that good.

BR, Nick