Dynamic Contrast Ratio, what the heck?

Question

what is the difference with dynamic contrast ratio, and native contrast ratio.

I notice alot of HDTVs say they have an enormous dynamic contrast ratio in the tens of thousands to one, while the native ratio is something like under 2000:1.

Looking to help my dad pick out a TV and i know enough to help him out, except this.

is dynamic something you just switch on?

Any help is appreciated, THANKS!

Answer 1

Dynamic CR is a marketing gimmick, first used by Samsung, and completeley useless as a spec.

It defines the ratio of white/black BUT at different backlight levels.

So you get the brightest white with the backlight full on and the darkest black with backlight as low as possible. Of course in a scene, that never happens - even with dynamic backlight.

There are TVs now that if they sense that the whole scene is black, they can even turn off the backlight. That takes Dynamic CR through the roof, but of course it is completely meaningless.

Answer 2

This is a complicated issue because there is no standard of measurement that all makers use.

So, they all cheat to some degree to get a higher number. The only thing you can really do is 1. compare to numbers within a brand and 2. pay attention to the native contrast ratio rather than the dynamic.

Plasma usually can display a greater constrast ratio. LCD had a hard time getting out of the 1000 to 1 and 3000 to 1 ballpark and use dynamic ratios that are up to 50,000 to one and beyond.

LCD uses a backlight that's always on, only the pixels twisting and unstwisting either block or allow light to pass. When in an off state, some light could still leak through, hurting the contrast ratio. So LCD makers turned to back lights that can change their levels.

This isn't perfect because you darken the entire image. Now there are new sets with local dimming (using multiple LCDs) but their price can be very high.

So ignore the dynamic number, and compare within brands, The more expensive samsung for example, generally have better native contrast ratios than the cheaper samsungs.

For better constrast if you don't plan on playing video games or connecting a PC skip LCD and get a plasma.