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I am looking to buy an upgrade monitor and want something wide (ish) gamut for lightroom post processing. Ideally I'd like 16:10 monitor and at least 98% of AdobeRGB as mentioned in this thread:

What are the merits of a wide-gamut display in post-processing for web?

I am considering the:

http://www.samsung.com/uk/consumer/pc-peripherals/monitors/professional/LS24A850DW/EN-spec

From it's specs which state 16.7 mil colours, I have no idea if its wide or wide-ish gamut? Can anyone tell from the specs?

Thanks,

Steve

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4 Answers 4

Gamut and color count are not really the same thing, although a low bit depth will start to affect gamut to a degree (i.e. a 6-bit flat panel will never be wide gamut, simply because its sampling of the color space is too sparse.)

Gamut describes the range of colors, from the total L*a*b* space, that a monitor is capable of representing. Many monitors are only capable of reproducing the sRGB space, which would be "standard" rather than "wide". Anything that approaches or surpasses the AdobeRGB space is "wide". It is important to note that even though sRGB monitors are not wide gamut, it is still capable of displaying 16.7 million colors just like a wide gamut display.

enter image description here

The difference is the "extent" of the mapping of those colors. On an sRGB display, the most saturated and pure green will not be as saturated and pure as the most saturated and pure green on an AdobeRGB display. (See image above for mapping extents of sRGB relative to AdobeRGB and the full visible color space, or Lab). Similarly, although to a lesser degree, the same goes for the most saturated reds and blues. Having a wide gamut display means your colors can be richer, purer, and more expansive, even though the screen still displays the same number of colors.

It should be pointed out that with displays that use RGB LED technology, the source light itself is purer, and allows gamut coverage of over 100%...sometimes as high as 130-140%. Combined with higher bit depth of 10 bits, these displays are capable of displaying at least 1.07 billion colors with considerably richer, smoother rendition of a more extensive and complete color palette. Such a display would be ideal for photography.

As for the specific monitor you have linked, I see no evidence it is a wide gamut monitor. It seems to be a fairly standard monitor built with LED backlight technology. I wouldn't expect much more than sRGB performance out of it. To my knowledge, Samsung does not currently produce any wide gamut desktop displays. The only time "wide gamut" is associated with Samsung is in reference to some of its more recent Galaxy smartphones. If you want a wide gamut display, you will need to look into Dell, Apple, NEC, Eizo, etc. Personally, I think NEC has a corner on the price/value sweet spot, with high quality monitors using 14-bit hardware LUT (1.07 billion colors) and high quality hardware calibration for a reasonable price point. Dell offers some screens with 12-bit hardware LUT, however their screens often have an oddball antireflective coating that evokes more hate than love from photographic professionals. Dell UltraSharp screens will be the cheapest "quality" wide gamut displays on the market.

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Just to be super-clear: a 6-bit panel could be made to be wide gamut, but it in the real world, it would be unlikely because it would be hard to cover the whole spread nicely. –  mattdm Jun 15 '13 at 17:34
    
you could make a 1 bit display with a wider gamut, but it would be pretty ugly. I guess that's what an array of 1W lasers would look like - you could always PWM them :) Wdith and coverage should be separated as terms. –  Michael Nielsen Jun 15 '13 at 21:32
    
@mattdm: Aye, that is exactly what I mean. A six-bit display can only "sparsely" cover whatever gamut you try to cover, hence making it otherwise not worth while to try and make a 6-bit display a "wide gamut" display. –  jrista Jun 15 '13 at 22:40
    
When you say such a screen is ideal for photography, what do you mean exactly? I can understand it is ideal for the photographer to work with the photo in the most rich and accurate way. Perhaps it is also ideal for print? What about digital delivery though? If none of your customers have access to the kind of screen the photographer has, how does this kind of screen add anything compared to using a screen common to one the average citizen will be using? –  Ferdy Jun 18 '13 at 19:53

16.7 millions colors is one way of describing a 24-bit monitor. It is capable of displaying each of the three colors used to produce all color on your monitor in 8-bits. That means it can display 256 levels of red, 256 levels of green. and 256 levels of blue. Thus, the total number of possible combinations is 256*256*256 = 256^3 = 16,777,216. That doesn't really tell you how wide those 16.7 million combinations are, though.

The best information I can find regarding Samsung monitors is that the models in the 95% range at one time had a "T" in the model number. Although I could find no direct source that verifies it, I did come across a couple of references that describe the Samsung S24A850DW as a "normal gamut" monitor.

As the answer to the question you linked to at the beginning of your question explains, if your images are meant for web publishing, they need to be in standard sRGB because the vast majority of monitors in existence are not capable of the wider AdobeRGB color space. Images produced in the AdobeRGB color space will not display correctly on most sRGB monitors. Even if a potential viewer's monitor does support AdobeRGB, it is very possible their browser doesn't, and will try to display the image as an sRGB image.

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One little nit pick: images *produced* in AdobeRGB should really be images *tagged with* AdobeRGB. You can produce images in any color space you want. What matters is that they are converted to and tagged with the target space so that the images are rendered appropriately to downstream viewers. Remember, RGB is RGB, if it's 8-bit every color component will always have a range of 0-255. What matters is how those colors are MAPPED WHEN RENDERED. The mapping is really what gamut refers to. –  jrista Jun 17 '13 at 17:10

You can read extensive revies and tests of gamut coverage, viewing angles, fitnees for photo work , etc. here:

http://www.tftcentral.co.uk/reviews.htm

Doing a quick search on the review page for "wide" you can get to some wide gamut options quickly.

There is a Selector tool where you can input that you need a wide gamut for photo work:

http://www.tftcentral.co.uk/selector.htm

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Short answer is no. The amount of colors is the bit depth of the process, not the gamut. The higher the bit depth the greater the color resolution of a display or color process.

When you're talking gamut, you mean the brightest primary and secondary colors. Usually that comes with display brightness, although some displays have added some through the purity of the display primaries.

So Gamut size is directly affected by the white point of the process. If everything is equal, the brighter monitor or brighter media will produce a greater gamut. Of course when we're talking media be careful that optical brighteners are not fooling you into thinking one paper is brighter than another. These fade when exposed to light and can be tested for with a black light.

Back to your monitor question: That display is a wide gamut display. Be careful though if you plan to use it for color critical work because this is not a display for that. This is Samsung's LED Business Monitor. So great for desktop backgrounds and Excel, but not for high end color critical work.

LED backlights are generally a system to stay away from when it comes to color accuracy. Their use in displays is more for blacks than color, because it allows the monitor to turn off the LED behind a black pixel. Problem with LED colors is they produce a very spiky spectra and are not good for color accuracy.

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LED backlights can be just as color critical as CFL backlights. The LaCie 730 offered one of the widest gamuts possible at around 124% Adobe RGB. It was a Matrix RGB LED display with local dimming, hardware LUT, a mere 200cd/m^2 bright. & 1000:1 contrast, and two selectable rendering modes: CIE 1931 & 1976. The majority of LED screens use edge lighting, rather than matrix backlighting, so they don't generally support local dimming. But LED backlighting, particularly RGB LED, is most certainly capable of producing highly accurate and very saturated color if you need it to. Sadly, the LaCie –  jrista Dec 18 '13 at 22:30
    
I'd also offer in contrast, two of the best monitors for color-critical work on the market today, Eizo ColorEdge and NEC PA series, are both CCFL backlit, and support at most 97.1% AdobeRGB coverage. Neither of these monitors are cheap, both are highly respected in the field, and both produce rich color and excellent tonal gradient...yet both fall far short of LaCie's RGB LED design. I think RGB LED was a bit ahead of it's time when the LaCie 730 was released (years ago now), and I am hoping the technology returns with 4k 32" RGB LED displays. –  jrista Dec 18 '13 at 22:35
    
Your information on LED lighting is incorrect also. For the past 10 years CIE division 1 has been battling about the best method to measure CRI (Color Rendering index) in LED lighting. Why? Because the standard measurements don't work. Why? Because the LED spectra is too spiky, and highly metameric. The best monitors don't use LED backlights for that very reason. Stop by one of the CIE meetings and say hi, next time your in town. –  R Hall Dec 18 '13 at 22:45
    
When it comes to basic LED lighting, I agree. A significant part of the problem is that "white" LEDs are not actually white at all, and thus are incapable of reproducing a useful color spectrum. The entire point of using RGB LED lighting is to produce pure source colors...to purposely produce "spiky" red, green, and blue bands without anything inbetween. We blend color from only those three color components, the mathematics behind them don't expect any intermediate color for the discrete color components of a pixel. So RGB LED is more accurate than both "white" LED and CCFL. –  jrista Dec 18 '13 at 23:00
    
When you use CCFL or white LED to backlight a screen, you have a loss of contrast as light that SHOULD be blocked by the color filters of each pixel leaks through. The benefit of using only narrow band red, green, and blue source light is you don't have as much excess light to filter out. Red light is easily allowed through red pixels, green light through green pixels, blue through blue pixels. The narrow bands are easier to filter by the opposing two color filters. The backlight can be brighter. Richer blacks. Brighter whites and pure primaries. –  jrista Dec 18 '13 at 23:08

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