LCD's = incapable of color accuracy

[Scyles]

A picture from engadget's preview of Samsung's upcoming "local dimming LED" technology (on the right):

Full article: http://www.engadget.com/2007/02/01/samsungs-15-4-30-and-40-inch-led-backlit-lcds/

What this shows us is a comparison between our standard ~1000:1 contrast ratio LCD's and Samsung's new, allegedly, 100,000:1 contrast ratio LCD (like a CRT). In a darkened room, the differences in the blacks would be highly noticeable, but what we really notice here is the total failure of the LCD on the left to accurately display the red tones. <EDIT> Looking at the picture again, I feel that this is Samsung's deceitful marketing division at work. I've got an S-PVA and a CRT side by side. I put up a very similar wallpaper for comparison, and though the difference in the blacks was apparent, the difference in the dark red areas is something you have to actually look for to see. </end edit>

I notice a lot of people come here looking for an LCD, saying that color accuracy is important to them. With contrast ratios as low as 1000:1, you'll never have it. With TN and VA panel color shifting due to viewing angles, you'll never have it. Eizo, be damned. So, tell me if I'm missing something critical in this conclusion.

This local dimming LCD technology looks exciting, but I forsee a few problems with the precision and response time of the backlights. Even so, this should be a good replacement for current dynamic contrast ratio solutions. Wait and see...

 

[kimnkk]

Looks like another gimmick like 'dynamic contrast' was. But i guess we'll see if this becomes the new standard...

 

[jcll2002]

we'll see. id love that 30"er but i know its going to be like 3k

 

[Snowdog]

The only one with local dimming is the 40" and it is 1366 x 768 resolution and will probably cost a small fortune.

Local dimming is much better than dynamic contrast as it can turn down sections of the screen rather than the whole screen at once. It would be a nice feature to have if it wasn't so expensive. Brightside are the only ones to deliver an LED local dimming LCD and they charged $15000.

LG is also coming out with a 1920x1080 S-IPS local dimming TV. That would be the one to get IMO, but it will also be very expensive.

 

[bootstrap]

What this shows us is a comparison between our standard ~1000:1 contrast ratio LCD's and Samsung's new, allegedly, 100,000:1 contrast ratio LCD (like a CRT). In a darkened room, the differences in the blacks would be highly noticeable, but what we really notice here is the total failure of the LCD on the left to accurately display the red tones. <EDIT> Looking at the picture again, I feel that this is Samsung's deceitful marketing division at work. I've got an S-PVA and a CRT side by side. I put up a very similar wallpaper for comparison, and though the difference in the blacks was apparent, the difference in the dark red areas is something you have to actually look for to see. </end edit>

I don't know about Samsung's deceitful marketing, but you obviously can't see the correct difference between the two in a picture unless the monitor you're viewing them on has the same color space as the monitor on the right (and the camera used the same color space, etc). On my display, the left picture looks much much better -- the right simply looks like what I would get if I turned my contrast way too high.

I think part of the confusion is that people use terms like "accuracy" very informally sometimes, while people talking about having a monitor with good color accuracy mean something much more precise. Color accuracy measures how closely the color displayed on the monitor matches the color that it's supposed to be displaying -- thus, it's a measure within the monitor's color space. The Eizo does have extremely accurate color -- it's not capable of producing all the reds that the Samsung can produce because the Samsung has a wider color gamut (i.e. it can display more saturated, "redder" reds), but this is an entirely different issue than its ability to faithfully reproduce a color.

Sorry if you already know all this, but for those who have never seen it, here is an illustration of a color gamut. The gray area is the full space of colors that we can see -- a monitor that displays colors by using combinations of three colors will be capable of displaying colors within a triangle -- this is its color gamut. Note that the color gamut for a typical monitor is much smaller than the entire space of colors that we can see. A wider color gamut means that the Samsung has a bigger triangle than the Eizo. "Accuracy" describes how close the color on the monitor appears to the color it thinks it's pinpointed within the triangle.

So I think that some of the confusion might be that you're using the term "accuracy" differently than others -- perhaps "realism" might be a better term? In order for monitors to be more realistic, they have to both increase the color gamut to be able to display a wider range of colors, and display colors within that range more accurately. Contrast ratio is another issue entirely. It measures the ratio of the luminance of the brightest white to the darkest black, and by itself it doesn't tell you much about color (a grayscale monitor could have an extremely high contrast ratio, it doesn't mean it will have very good reds ). In terms of the color gamut diagram, lowering the luminance would make the entire triangle appear less bright, so this is actually another entire dimension of the problem that needs to be addressed in order for displays to be more realistic.

 

[xtknight]

Color accuracy isn't really dictated by contrast.

Your average 'good' consumer LCD (i.e. Samsung 215TW, NEC 20WMGX2) can reach a deltaE of under 0.70 for all tones, properly calibrated. If you think about it, contrast should really only matter for the tones between 0.00 nits and the monitor's black level. Beyond that, it should be able to display every other color with a 0.40 (i.e. black level) nit offset, which can be reversed through calibration. Clearly, one of those monitors is pretty uncalibrated.

 

[interpolator]

I use my Gretag Macbeth color checked chart to really test and validate the color accuracy of these monitors. With LCD monitors it is never close to the color checker on a number of colors. I like to believe alot of the problem is the inability to really fine tune the look up tables in the displays; but the LCD technology has its limits and Samsung's application is no exception. Often I get ready to give up and say LCD is good enough. Again several nights ago I had an epiphany when I attached my Canon XH-A1 camera to a 20 inch Sony broadcast monitor I had just had recently calibrated. Every color on the Gretag chart was perfect as displayed on the monitor. I have yet to see an LCD monitor that can do this.

 

[Velocities]

I say there is excellent color accuracy LCD out there. One of them is Apple 23 Cinema HD Display, and the other is Eizo. Apple use IPS Panel, and color is really good. I own an 23 ACD before and it have better color accuracy then my Viewsonic CRT. Consider IPS Panel if you want the best color accuracy.

 

[joemama]

I say there is excellent color accuracy LCD out there. One of them is Apple 23 Cinema HD Display, and the other is Eizo. Apple use IPS Panel, and color is really good. I own an 23 ACD before and it have better color accuracy then my Viewsonic CRT. Consider IPS Panel if you want the best color accuracy.

I think most people here know that IPS panels are good compared to OTHER lcd technologies....but still fall behind crt's for color accuracy. I fall into the group that would like to have color accuracy..but don't really need it for my job or at home. If the grass in WoW is not the exact shade of green the developers intended...then so be it.

 

[ToastyX]

I don't know why people keep saying the Apple Cinema Display is good for color accuracy. It's not accurate out of the box, and it can't be internally calibrated. It's no better than other monitors with S-IPS panels. In fact, it's worse because it doesn't have any adjustments other than luminance. At least the Sony SDM-P234 can be adjusted before calibration, which results in more accurate colors, and it costs less as well. Still, only high-end Eizo and NEC monitors are very good for color accuracy. Others are just okay, nothing special.

As for color gamut, that has to do with what colors it can display, not how accurate they are. Most LCD monitors these days have the same color gamut as most CRT monitors, and a few high-end LCD monitors even exceed the color gamut of most CRT monitors.