Playing the numbers game is nothing new in the audio-video industry. Companies in the 1970s and especially in the 1980s tried to show that their receivers had bigger amps than they really did. Speaker specs were fudged to make them look more efficient that they really were. The role of THX certification and the awareness that came from it put an end to this gamesmanship. Yet today’s video manufacturers are back at it, suggesting that a video projector has a 10,000:1 contrast ratio, yet not disclosing that they measure the contrast inside the projector.

AVRev.com video guru, professional video calibrator and Imaging Science Foundation instructor Kevin Miller suggests a number of points about contrast that try to shed a properly calibrated amount of light on the topic.

The Full On/Full Off Method
The Full On/Full Off method that is used to measure and calculate contrast ratio has no validity in the real world, says Miller. Some manufacturers crank the display's contrast to the max, and measure one pixel in the center of the screen to get the white reading. Then they take the signal out of the display altogether to measure a perfect black in a perfectly black room. This results in huge contrast ratios, yet has little to do with any real world situation that you will have in your system – even in a light-controlled dedicated home theater.

The ANSI Method
The ANSI method is done by first calibrating white and black levels properly, measuring a “checker board” black and white pattern, averaging all of the white squares and all of the black squares and then dividing the white average with the black average. When you do this in your theater, you will have the contrast ratio that your display is capable of without severely distorting the picture or, in other words, a more real world number.

Miller goes on to suggest, “Today we have contrast ratio wars, which is akin to what projector manufacturers were doing with light output in the 1990s, with what Sam Runco so accurately called ‘bullshit lumens,’ as opposed to ANSI lumens.”

To me, the outlandish reported contrast ratios remind me of when golf club manufacturer Cobra decided to lower the lofts of all of their irons in the 1990s. All of a sudden, a Cobra 7 iron would go 10 yards (or more) longer than a comparable Ping or a Titleist 7 iron. The reason was that a Cobra 7 iron had the loft of a 6 iron, but consumers at their local country club’s Demo Day didn’t know the difference. All they knew was that their 7 iron has never gone that far and they were buying some Cobra irons. All of the other club manufacturers followed Cobra’s lead and lowered their lofts to compete and most golfers today now carry an extra wedge to make up the difference.

I don’t mean to understate the importance of contrast in the research you do when looking into any video display. Contrast is incredibly important to the quality of your image. What I am suggesting is: take the number that the manufacturer reports with a grain of salt if you think the number might be too good to be true. At a recent ISF training session, I watched as the instructor calibrated a CRT HDTV known to have “the best blacks you can buy” with measurements using the ANSI method of less than 200:1. Compare that with a projector manufacturer who says that their three-chip DLP projector has 10000:1, and you know who is trying to pull one over on you. In the end, trust your eyes. Proper calibration is something you don’t want to live without for systems ranging from an entry-level Vizio to a top-of-the-line Runco projector, but in the final analysis, you have to love the way a display looks, not the way the display’s stats look on a spec sheet.


Want to receive more news like this directly in your email box once a week? Sign up below for the AudioVideoRevolution.com weekly email update list.

First Name
Last Name
E-mail address	Can you receive HTML e-mail? Yes No