The WOW! Buzz

We’ve talked generally about how LCD HDTV has improved substantially over the last few years. One of these specification improvements is contrast ratio, expressed as “xxxxxx:1. It is an expression of the difference between the “brightest white” and the “blackest black” that a display can muster. Over the past few years, set specifications have improved considerably in this area, and most would agree that newer LCD sets are indeed more capable of displayed greater contrast detail than they were a few years ago.

The problem is that the published specification itself has become almost meaningless. Set manufacturers have created a numbers game, some claiming a contrast ratio of 1,000,000:1 or more. Some years ago, a very good panel set would publish a contrast ratio of 1,000:1; now that same television would likely sport a specification of 20,000:1 or greater, simply because manufacturers have changed the way in which they measure this specification in the race to win against competition. The only real “standard” out there is a ANSI based test using a checkerboard pattern like that displayed here and a standard testing procedure to measure performance in this area–a completely valid test, but one which produces numbers that are much lower than the present competitive market will bear.

I haven’t run into any consumer quality manufacturer who publishes the specifications associated with this standard test much anymore; They typically use self defined standards like “dynamic contrast ratio”. What does that mean? It means that the set manufacturer is publishing a specification that is essentially meaningless, and inflated relative to the sets actual ability to perform in this area.

Just for illustration, one of the world’s most popular professional digital cinema projectors, the Christie CP2000 DLP Cinema, has a contrast ratio rating of only 500:1 ANSI, and, it produces a very good image, with very subtle differences in grey scale and color. The specification here that is perhaps most telling is that Christie claims the ability to produce over 35 trillion colors/levels of grey on screen. This projection system is widely deployed in cinema theatres throughout the world.

The point is this. In this particular, trust your eyes to make the judgement on the ability of the HDTV to produce a lifelike picture with as much detail as possible, and contrast between black and white. Choosing one HDTV over another based on the difference in published contrast ratio alone wouldn’t be prudent in the current environment.

There are signs that some manufacturers are “wising up”. Several have stopped publishing a contrast specification altogether, acknowledging the numbers game is counter productive. I applaud that approach–a better one would be to consistently use the ANSI standard for this specification to allow true comparisons between sets. But even then, the eye really is a much more sensitive and accurate device in determining ultimate picture quality.

On another subject, it is the wish of the Technology Team at WOW! that all of you have a very peaceful and joyous Holiday Season.  Best Wishes to you and yours.

Steve Stanfill