What Does Contrast Ratio Really Mean?

Reader Jim writes: How much of a difference does the contrast ratio on LCD TVs make?  Is 8000:1 really that much better than 1000:1 for contrast, and worth the extra price?

Contrast ratio is perhaps the most misleading and overhyped data when it comes to televisions. In theory, contrast ratio measures the difference between the brightness in the super-bright portions of a screen vs. the super-dark portions. A 1000:1 contrast ratio would mean that a perfectly white pixel is 1000 times brighter than a perfectly black pixel.

That's the theory, anyway. The problem is that these brightness levels are hard to calculate, and they're subject to all sorts of interpretation. Ultimately, contrast ratio has become little more than marketing-speak, and the numbers are now largely meaningless. Things have gotten out of control to the point where various vendors have claimed 1,000,000:1 contrast ratios. It's getting to the point where escalating contrast ratios are now an industry joke, though not a very funny one.

Gizmodo has an extensive piece on the topic, which rightly points out that high contrast ratios don't mean high brightness. Rather, companies have focused more recently on decreasing the brightness of the "1" side: making the blacks blacker instead of the whites whiter. As the post notes, "Cutting the darkest dark on a screen by .5 effectively doubles the contrast ratio." In comparing an 8000:1 TV to a 1000:1 TV, you're probably looking at a TV that the manufacturer claims has richer, truer blacks.

Of course, it may not. The numbers could be calculated differently, inflated, who knows. You'll need an independent source (probably from a high-end home theater publication) to get a real sense of a TV set's contrast, but even then the numbers probably wouldn't be very meaningful because of the difficulties in performing such a test.

Ignore manufacturer's contrast levels and focus instead on how a TV looks to your eyes, whether it has the connections you need, and if it's the right size for your room.