TV & Home Theater

[islandgymnas]

How much does the dynamis contrast ratio matter in a 40" LED HDTV? Will there be a huge difference in quality between 30,000:1 and 5,000,000:1 in a TV from the same manufacturer?

[NoNoBadDog]

There is no lasw that regulates how contrast ratios are measured on TVs.  The number is completely meaningless.  The higher the number, the less liekly it is that the number represents a real world measurement.

Manufacturers can use whatever methodology they wisk to generate a number representing their claims of dynamic contrast ratio.  How they arrive at that number is not regulated...only that they can show how the number was achieved.  Manufacturers devise artificial tests to generate artificilaay inflated numbers, numbers that are meaningless in any real world scenario.

Add to the fact that the human eye has a rather narrow ability to detect contrast ratios, and the problem becomes more cloudy.

In short, you can completely ignore contrast ratios.  They are not a standard measurement.

Also, when shooting something through either digital or film cameras, lighting is such that the scenes being shot have a noarrow contrast range so that the whites don't bloom and the blacks don't ink over when being shot, so any means of delivering a contrast ration hiogher than the source material is wasted. 

It all boils down to marketing....for those that shop by specs instead of shopping by picture quality, the artifically inflated contrast ratios will make it more likely that a particular unit will sell better. 

[Entropy]

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islandgymnas wrote:

How much does the dynamis contrast ratio matter in a 40" LED HDTV? Will there be a huge difference in quality between 30,000:1 and 5,000,000:1 in a TV from the same manufacturer?

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DCR is worthless and meaningless.

Native contrast ratio is pretty important, but dynamic contrast is stupid.  It operates by changing backlight brightness depending on scene brightness.

[JoeB4ever]

NoNoBadDog hit the nail on the head. The only time I would pay any attention to them is if you're comparing the same brands. I think the only reason they rate the contrast ratio is so you can have something measurable to compare the televisons.

[AgentM]

It is quite true that 'dynamic contrast' is completely arbitrary and has no specific guidelines. Static contrast however is very measurable and visually tangible, but much less impressive of a number and rarely advertised. Static contrast is the difference between the brightest white and darkest black the TV can produce.

Bottom line, dynamic contrast is essentially advertising hokum, it has no 'real-world' meaning and every manufacturer can use whatever method they wish to come up with the number.

Go by the TV that looks best to you, after all, you have to watch it every day. Compare  them side by side and go with the one that looks the best without consideration for the numbers on the box (except price number of course).

-Agent M

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[Entropy]

Yup.  Static (I called it native) contrast ratio is important - frequently this will be on the order of 10,000:1 (for a REALLY good TV) or lower.  Maybe things have improved since I last bought a TV.

It is often very difficult to find the native contrast ratio of a TV.

[DarkWingDUCK]

The best thing you can do is look at the TVs you are interested in at a store and set them all to their Movie or Cinema picture modes.  Compare the accuracy of the colors, do not compare how "poppy" and "crisp" the colors are.  Try to watch something that uses widescreen bars on the top and bottom of the screen and see if any CCFL or LED lighting bleed through and oversaturate the blacks.  You want those blacks deep, dark, and inky. Since many TV manufacturers dont publish their native contrast ratios, you can use this method to determine better contrast by eye.  It is not the most scientific means of doing it, but it gets you close.

[mkn0927]

You also want to look for shadow details.

See if the TV you want has the blackest black AND observable details in the shadows.