How much of the sRGB color gamut can be displayed on your LCD monitor?
The very commonly used sRGB working color space was based on the display characteristics of CRT monitors, which meant that any decent quality, calibrated CRT could display the entire sRGB color gamut. An obvious yet somehow overlooked question is whether the entire sRGB color gamut can be displayed on today's LCD monitors. For many LCD monitors, even many wide-gamut LCD monitors, the answer, alas, is no.
Assuming you have a reasonably accurate profile for your LCD monitor, this article shows you a quick and dirty method for checking how much of the sRGB color gamut your LCD monitor can display, and provides results for several example LCD monitors.
Written July 2013. Minor updates made in February 2015.
While perusing the various photography forums, sometimes I run across the claim that when shooting raw, if you convert the interpolated image to sRGB, you can see all the image colors on your monitor.
Fifteen years ago, in the heyday of CRT monitors, anyone using a reasonably high quality, properly calibrated CRT monitor could say with confidence "Yes, my monitor can display all the colors in an sRGB image." Is this claim still true if you are using an LCD monitor?
This article examines profiles for three LCD monitors — two models current as of 2013, one retailing at $2500 and the other at $450, and an older model that retailed at $1200 — to determine which portions of the sRGB color gamut these monitors can and can't display. The $2500 and $1200 monitors are/were aimed at the professional photographer. The $450 monitor is aimed at the enthusiastic amateur photographer. If you are curious, you can follow the procedures outlined below to check your own LCD monitor's color gamut.
All the sRGB colors
Bruce Lindbloom's RGB Image Containing All Possible Colors is an amazingly useful test image. Screenshots of the RGB16Million test image are used with the kind permission of Bruce Lindbloom, which in no way implies that he endorses my findings! To the right is a screenshot of Bruce Lindbloom's RGB16Million test image, after assigning the sRGB color space profile. Each pixel has a different color (different set of RGB values), covering all possible colors in an 8-bit image.
Having assigned the sRGB color space to the RGB16Million test image, in theory any decent-quality, well-calibrated CRT could have displayed 100% of the colors in this test image. As the pictures below will demonstrate, at least as of 2013 the same claim can't be made for decent-quality LCDs.
What percentage and which portions of the sRGB color space can you see on your LCD monitor?
The following "monitor profile color gamut checks" were be performed using an ICC profile color managed image editor that provides for soft proofing gamut checks. The procedure requires that you have chosen an accurate display profile for your LCD monitor. Monitor profiles can be downloaded from the internet (see ICC Profiles and Monitor Settings Database and Colour Calibration Profiles for your Monitor, and of course check your monitor manufacturer's website). Monitor profiles really are machine-specific, so for a known accurate profile you should calibrate and profile your monitor yourself.
Color gamuts of LCD monitors vary greatly from one make and model to the next. Results for three monitors aimed squarely at professional and enthusiastic amateur photographers are given below. Screenshots of the RGB16Million test image show which portions of the sRGB color space fit within the color gamut of the monitor profile for each monitor. The percentage values for how much of the sRGB color space each monitor can show were estimated using the Arygllcms iccgamut and viewgam utilities, using CIELAB as the reference color space.
Recent wide gamut professional-level LCD monitor. The magenta splotches (look closely at the upper edges of the color squares in the lower half of the test image) indicate colors in the sRGB color space that this professional-level LCD monitor can't display. These "out of gamut" sRGB colors that this monitor can't display encompass the more saturated sRGB blues and magentas.
This monitor is currently priced around $2500. It has received rave reviews for its color accuracy. It can display somewhere well north of 96% of the colors in the sRGB color space. Most LCD monitors marketed as "wide gamut" aren't quite as wide as this one!
Circa 2006 professional-level LCD monitor, not wide gamut, originally priced somewhere north of $1200. This monitor also received rave reviews for its color accuracy.
This monitor misses all of the same portions of the sRGB color space that the previous monitor misses, but the magenta splotches are slightly larger, plus there's some additional magenta splotches in the squares along the upper edge of the test image. This monitor can display around 93% of the colors in the sRGB color space.
Recent consumer-level LCD monitor, currently priced around $450. Reviews indicate that for image editing this monitor is one of the better consumer-level LCD monitors available on the market.
This monitor can display around 88% of the colors in the sRGB color space. Notice that not just the size but also the shape and position of the magenta splotches has changed compared to the previous, professional-grade monitors.
Which colors can your LCD monitor display, that exceed the sRGB color gamut?
We've considered the question of "what percentage of the sRGB color gamut can today's LCD monitors actually display" and found the answers to be 96+%, 93%, and 88%, respectively, for a recent high-end wide gamut monitor, an older high-end but not wide gamut monitor, and a recent consumer-grade monitor.
We've also seen that which range of sRGB colors can't be displayed on any given LCD monitor varies from one LCD monitor to the next, with the high-end monitors having very similar ranges of colors that can't be displayed, and the consumer-grade monitor having a very different range of colors that can't be displayed.
Now let's turn this little examination on its head and ask, "How many colors can an LCD monitor display, that exceed the sRGB color gamut? In the following screenshots, magenta indicates a color that is inside the monitor's color gamut, but outside the very small sRGB color gamut. If you shoot raw or scan in film and then immediately output your images in the sRGB color space for further processing, the magenta splotches represent colors that you could have seen on your monitor if you hadn't thrown them away by converting the image to sRGB.
Recent wide gamut prosumer/professional LCD monitor, currently priced around $2500. The magenta splotches indicate colors that this monitor can display, that exceed the very small sRGB color gamut. Approximately 30% of the colors that this monitor can display fall completely outside the sRGB color gamut. So if you convert an image to sRGB you are potentially throwing away (depending on the image color gamut) a whole lot of colors that your pricey monitor can display.
By today's standards, this monitor has a very large color gamut, by volume considerably larger than the sRGB color gamut. It exceeds the sRGB color space in greens and cyans by quite a bit (which is why the magenta splotches are covering up a lot of the green and cyan colors in the test image) and it exceeds the sRGB reds by a little bit. However, as we saw in the previous section, despite being so large, the color space defined by this monitor profile still fails to encompass some of the more saturated sRGB blues and magentas.
Circa 2008 prosumer/professional LCD monitor, not wide gamut, originally priced somewhere north of $1200. Approximately 16% of the colors that this monitor can display fall completely outside the sRGB color gamut.
By today's standards, this monitor has a large but not wide gamut color gamut. It exceeds the sRGB color space in greens and cyans (though not nearly as much as the $2500 monitor), and in the reds by a little bit. The color space defined by this monitor's profile is also larger by volume than the sRGB color space, but just like the preceeding monitor, it fails to encompass some of the more saturated sRGB blues and magentas.
Recent consumer-level LCD monitor, currently priced around $450. A mere 3% of the colors that this monitor can display fall outside the sRGB color gamut. A whopping 12% of the sRGB color space gamut falls outside the color space defined by this monitor's profile.
Obviously this monitor's color gamut is smaller by volume than the sRGB color gamut and also much smaller than that of the preceeding two monitors. But compared to lesser consumer-level LCD monitors whose profiles I've taken the time to examine, this monitor's color gamut is actually pretty good.
The mismatch between many LCDs and the sRGB color space: implications for image editing
Now let's put the results of these two sets of percentages and softproofing images together and see what they tell us about trying to edit images in the sRGB color space while using an LCD monitor.
- Some professional quality wide gamut monitors can display almost all the colors in the sRGB color space:
- If you shoot raw and immediately convert your images to sRGB for subsequent processing, you really can see (almost) all the resulting colors on your LCD monitor.
- But the price you pay is that you might have thrown away significant image colors (additional yellows, greens, and cyans) that you also could have seen on your wide gamut monitor.
- I don't know whether anyone still makes professional quality monitors that aren't wide gamut. But if you have such a monitor, or if you have a wide gamut monitor that isn't in the same class as the "widest of the wide gamut" monitors, then using sRGB as your working space puts you in an awkward position:
- If you shoot raw and immediately convert your images to sRGB for subsequent processing, it's entirely possible that some of the resulting image colors will be within the sRGB color gamut but outside your monitor's color gamut. So there's no guarantee that converting to sRGB means you'll be able to see "all the colors".
- And you also pay the price of potentially throwing away significant image colors that you could have seen on your professional-quality monitor if you hadn't converted the image to sRGB.
- What about the consumer-level monitor?
- If you shoot raw and immediately convert your images to sRGB so you can "see all the colors", it's pretty much a dead certainty that some of the resulting image colors will fall outside this monitor's considerably smaller-than-sRGB color gamut.
- The consumer-level monitor considered on this page has the advantage that its color gamut, though smaller than sRGB, is almost entirely contained within sRGB. Low-end consumer-level monitors can have color gamuts that are smaller than and only partially overlap the sRGB color space, thus hitting you with the double-whammy of not being able to "see all the colors" and also not utilizing your monitor's full color gamut.
Hopefully I've convinced you that the claim that "converting to sRGB means you can see all the colors" simply isn't true if you are using many, perhaps most LCD monitors. It's almost true if you are using a sufficiently high-end LCD. I found out after writing this article that certain Apple displays already can display all of the sRGB color space. It may be completely true for all monitors some day in the future as monitor technology continues to evolve and wide gamut monitors trickle down to the consumer level. But for most of us, right now, it's not true and hasn't been true since we retired our last CRT monitor.
LCD monitor profiles as seen from inside the CIELAB reference color space
Color gamuts are actually volumes of color located in a three-dimensional reference color space such as CIELAB. Figure 1 shows the view from inside the CIELAB reference color space for four different LCD monitor profiles. Each monitor profile color gamut is shown overlapping the sRGB color gamut.
As you can see from the LAB gamut views in Figure 1, the color gamut for the first LCD monitor's profile (the multicolored blob) entirely encompasses the sRGB color gamut (the white wire frame) while also including a considerable portion of CIELAB that falls outside the sRGB color gamut. Profiles for each succeeding monitor encompass progressively less of the sRGB color gamut.
The second and third LCD monitor profiles have color gamuts that do include a lot of colors that exceed the sRGB color gamut, but don't include all of the sRGB colors. I didn't have a V2 profile for the $2500 monitor discussed above, so I couldn't use the Argyllcms utilities to generate LAB gamuts, but picture something about half-way between the first and second monitor LAB gamuts shown above.
The fourth monitor profile for the consumber-grade LCD monitor has a color gamut that is significantly smaller than and almost entirely contained within the sRGB color gamut.
How to cope with the mismatch between sRGB and today's LCD monitors
What can you do about the mismatch between sRGB and today's LCD monitors? There are really only three alternatives:
- You can save your pennies, buy one of the high-end wide gamut LCD monitors and keep converting your images to sRGB, realizing of course that this color conversion throws away image colors that your very expensive LCD monitor is capable of displaying. If you follow this route, do your homework — a "wide-as-possible" color gamut isn't the only thing that makes one monitor more expensive than another.
- If you want to see all of your image colors on your monitor screen, and you don't want to shell out the big bucks for a high-end LCD monitor, then instead of using sRGB for image editing, you can make and use a custom working space that is as close as possible to your monitor's actual color gamut.
- This option also works if you are viewing your images on the widest-gamut LCD monitor available on the market today, and lets you make use of every scrap of the extra display color gamut that you paid so dearly to acquire, while still allowing you to "see all the colors".
- Just like converting to sRGB, converting to a custom working space tailored to your LCD monitor will still clip the more saturated image colors. But at least the resulting image will only contain colors that you can actually see on your LCD monitor, thus preserving the original reason for working in the sRGB color space.
If you use Argyllcms to make your custom monitor profile using the "several step" method (Typical usage Scenarios and Examples, Profiling in several steps), then you are already half-way to making your own monitor-sized working space. Just make yourself a second matrix monitor profile using the colprof "-aG" parameter instead of "-as". The resulting profile won't be a good monitor profile; instead it will be a working space with a color gamut that's very close to the color gamut of your monitor profile.
- Or you can learn the art of working in "wide open (color) spaces", as the esteemed Bruce Fraser so eloquently put it. By "wide open (color) spaces" Fraser meant any RGB working space whose color gamut sufficiently exceeds the sRGB color gamut so as to include colors produced by professionally scanned film and slides. Today we also want our "wide open space" to include colors captured by digital cameras when shooting raw.
Regarding option 3, editing in wide open color space, Fraser wrote his excellent article during the heyday of the CRT monitor, when you really could see all the colors in an sRGB image on your reasonably decent-quality and calibrated CRT monitor. Today's hard reality is that if you are editing images in the sRGB color space on anything less than the widest of the wide gamut LCD monitors, then technically speaking you are already working in a wide open space, "wider open" at least than your LCD monitor's neither sRGB-sized nor sRGB-shaped color gamut.
In my own digital darkroom I use a combination of options 2 and 3. Given the color gamut limitations of today's LCD monitors, it behooves us all to learn the basics of dealing with editing an image that has colors that we can't see on our monitors, because converting to sRGB no longer means you can see all the colors.
Summary and Conclusions
"Back in the day" a properly calibrated decent-quality CRT monitor could display all the colors in the sRGB color gamut. Unfortunately the same is not true for today's LCD monitors. Compared to sRGB and the old CRT monitors, even the $2500 and $1200 monitors are deficit in blues, though both of them can display greens and reds that exceed the very small sRGB color gamut. The $450 monitor? Although it appears to be one of the better consumer-grade monitors on the market today, it can display a mere 88% of the sRGB color gamut.
Why the mismatch between the sRGB color space gamut and the color gamut of today's LCD monitors? sRGB was created to match the display characteristics of consumer-grade CRT monitors manufactured in the 1990s. In particular, sRGB tristimulus values were chosen to be a good match to the type of phosphors used in consumer-grade CRTs. LCDs use a completely different technology to make colors, so profiling your LCD monitor will result in tristimulus values that are not the same as the sRGB tristimulus values.
LCD monitor profiles are available for download from several sources on the internet, hopefully you've already profiled your own LCD monitor, and I encourage you to make your own gamut checks. I examined profiles for several more professional/prosumer monitors (but not any of the ultra-expensive monitors with price tags north of $2500) and also for a sampling of consumer-grade monitors. Results were consistent with what's presented on this page. All wide gamut monitors by definition can show more greens, yellows, and cyans than sRGB. But only the "widest of the wide gamut" monitors can display (most of) the more saturated sRGB blues: compared to sRGB, the $2500 monitor considered above falls down precisely in the area of the very saturated blues. Some monitors marketed as "wide gamut" can't display all of the more saturated sRGB reds.
The good news is monitor technology keeps improving and color gamuts keep getting larger. But as you can see from the LAB gamut comparisons, at least as of 2013 although your wide gamut LCD monitor color gamut is no doubt larger than the sRGB color gamut, "larger than" doesn't mean "encompasses all of".