Are there any LED backlit LCD monitors with local dimming currently on the market?

[AMD_Fan]

My understanding is that the biggest advantage of LED backlighting, besides thinner panels and less energy consumption, is the ability to locally dim/turn off individual LEDs in order to achieve true-er blacks and mitigate backlight bleeding.

However, local dimming only seems to be enabled for LCD TVs. I have personally not been able to find a single LED-backlit monitor which uses the method, or maybe I have but it wasn't stated in the specs. And from what I've read, without local dimming LED backlighting can actually produce more bleeding. So I'm asking you, are you aware of such monitors? Can you give me examples?

Also, on a bit more technical tangent, can someone explain to me exactly how local dimming works? What's the average number of pixels that is lit by a single LED? How would it work if you had for instance a 2:39:1 movie playing and a bright scene was contrasting with the black bars - if an LED behind the black bar was turned off near the line where it meets the picture, wouldn't that affect the bright color of the picture as well? Thanks. Sorry for the long post.

 

[steal]

There aren't any, nope. Sorry

 

[Lunknumb]

There aren't any.

The only PC displays to use full array LED backlighting are the HP 2480zx and the top range LaCie displays, all of those are in the $2000-$4500 price bracket. Neither of those do any dynamic contrast cheats at all.

How can local dimming reduce bleeding? It's not like they will have sensors built in around the edges to detect where it bleeds and dim those areas. Bleeding is caused by faulty and/or low quality manufacting and can be avoided completely simply by building the display properly in the first place.

 

[JaguarSKX]

No monitors have local dimming.

Local dimming in HDTVs operate as follows:

The full LED array is divided into zones; for this explanation assume there are 256 square zones. Each zone backlights 8,100 pixels. Based on what is being displayed in each zone, the electronics of the HDTV will adjust brightness of each individual zone from between fully off (black) to fully on (white) and anything in between.

Since zones backlight chucks of 8,100 pixel, there will be times when you will see "white bloom" especially when veiwing from an angle, the greater the angle the more you will notice it. It basically means the backlighting can be somewhat uneven in a localized area because of various intensity colors being displayed.

The most extreme example of "white bloom" is a bright white circle being displayed on a black background. The white circle is direct in the center of 4 zones. Those 4 zones will switch on to 100% brigthness to display the white circle. The result is "white bloom" where the black in those 4 zones are not as the rest of the screen because the LED backlight in all other zones are turned off.

The more zones in a LED backlight array, the more expensive it will cost to manufacture.

 

[threeDguru]

Im currently using an Acer S243HL (LED backlit) and while it doesnt have local dimming, the blacks seem pretty accurate. Granted I do not have much experience with an array of monitors, but this once is doing a great job. Maybe take a peak at it.

 

[JaguarSKX]

^^^

It's uses a TN panel. TN panels have a reputation of having the absolute worst black levels.

Others may have less rigid standards compared to me so they may be "more forgiving" than I am.

 

[drleospaceman]

^^^

It's uses a TN panel. TN panels have a reputation of having the absolute worst black levels.

Others may have less rigid standards compared to me so they may be "more forgiving" than I am.

The latest TN monitors have better contrast ratios / black levels than the latest IPS monitors, at least according the the following reviews:

TN:
Acer H243H: Contrast ratio of 953:1
Dell G2410: Exactly 1000:1
Samsung 2233rz: 950:1
Acer's 120hz: 900:1

H-IPS & E-IPS:
Dell 2209WA: 630:1
Apply 24" LED Cinema Display: 740:1
Dell U2410: 666: 1
HP LP2475W: 793: 1

 

[mistar]

The latest TN's have better contrast ratios / black levels than the latest IPS monitors.

TN:
Acer H243H: Contrast ratio of 953:1
Dell G2410: Exactly 1000:1
Samsung XL2370: 960:1

Contrast ratio on Samsung XL2370 depends on the settings and calibration. Many Samsung monitors have terrible black crushing in the standard settings so if a reviewer measures contrast only in the standard settings or in the different profiles you might end up with a bad reference.

Here's a before and after measurement on Samsung XL2370: http://www.flatpanelshd.com/review.php?subaction=showfull&id=1265026060

 

[drleospaceman]

Contrast ratio on Samsung XL2370 depends on the settings and calibration. Many Samsung monitors have terrible black crushing in the standard settings so if a reviewer measures contrast only in the standard settings or in the different profiles you might end up with a bad reference.

Here's a before and after measurement on Samsung XL2370: http://www.flatpanelshd.com/review.php?subaction=showfull&id=1265026060

Fine disregard that one, but I have the 23" version of the Acer and it has absolutely no black crush.

 

[cygnusx-1]

I own 2 XL2370-1s for about 3 weeks now. Out of the box one was nearly perfect with no black crush and only a minor tweak to the Blue levels to get an amazing picture. The second had serious blue tint and crushed blacks and took about a half hour to massage a really decent picture out of. I expreienced none of the other issues (blacks are solid and even, whites are clean and crisp, no cloudiness, minimal bleeding) in that link and have to say it's the happiest I've been with an LCD in quite some time.