Color of the year for 2013 falls outside sRGB gamut

Pantone Emerald 17-5641

Pantone recently announced their color of the year for 2013, a deep shade of emerald green that they call “Emerald 17-5641.” It’s a great color but there’s a catch- most displays cannot accurately show it.

Based on data from Pantone’s website, I was able to plot the color in CIE 1931 (xy). As you can see in the chart below, Pantone’s color is well outside the sRGB/rec.709 color gamut standard used by most HDTVs, the new iPad/iPhone and many desktop monitors. These devices will be stuck showing a version of Pantone’s emerald green that’s less saturated and probably a bit more yellow than the real thing.

Pantone Emerald 17-5641 vs sRGB, Adobe RGB 1998 and DCI-P3 color gamuts in CIE 1931

This is a perfect example of a popular real-world color that falls outside of the sRGB/rec.709 gamut. Unless you have a monitor that’s able to show wider color gamuts, like the DCI-P3 or Adobe RGB standards, you are missing out on a great color.

So you bought a 4K TV, now where is the 4K content?

Content is king. One of the biggest challenges for emerging display technology is content availability. Whether it’s 3D, 4K or wide color gamut, these new features simply aren’t worth much without access lots of great, optimized content.

As new 4K TV’s begin hitting store shelves this year, they are entering a content vacuum.

Standards bodies like the Consumer Electronics Association (CEA) and International Telecommunication Union (ITU) are still working out the precise definition of marketing terms like Ultra High Definition TV (UHDTV). Proposed standards could include support for eight million pixel resolution, extremely wide color gamut and 3D content. But, today, there is almost no content out there that takes full advantage of all of the exciting capabilities of the new sets.

And, unlike the transition to HDTV, there’s no government-mandated switch on the horizon to force broadcasters to get on board.

CIE 1931 rec.2020 vs rec.709

At least one set-maker is taking it upon themselves to solve this problem by delivering both the 4K content and hardware. Sony announced last week that it will loan a 4K Ultra HD video player loaded with UHD content to buyers of their new 84” UHD television. The selection of 4K content on this player is fairly limited for now, but as more titles are released, this approach could help drive adoption of high resolution and wide color gamut formats.  I wouldn’t be surprised if other set makers started following suit, though Sony does have an inherent advantage, owning a movie studio.

Shopping for a tablet this holiday season? Don’t forget to look at color performance

If you have been researching the perfect tablet to give to a loved one this holiday season, you’ve probably read a lot about display quality. Tablet display size, resolution and aspect ratio have been discussed at length this year, which is really no surprise, since the quality of the display has the biggest impact on how we enjoy content on these devices.

What is surprising though is that color performance, one of the biggest differentiators among the current crop of tablet displays, has been largely glossed over by the mainstream gadget press.

The Verge’s tablet comparison tool, for example, gives great info about pixel density, aspect ratio and touch capabilities, but color performance is nowhere to be found:

Color is being ignored in spite of the fact that there are tremendous differences in the color performance of each of these devices that directly impact the consumer experience on each.

So why are we overlooking a feature that, unlike many of the features we focus on these days, presents a real difference between devices?  I see a couple reasons. First and foremost, thanks to Apple’s marketing of the Retina display, pixels-per-inch has become the spec du jour in today’s device wars.  Device makers are focusing their marketing efforts on pixel count above anything else.

Aside from current trends, I believe there’s also a macro reason to why color has been left out: color performance is just hard to compare. There is no universally accepted spec that can sum up color performance across devices.

Take the three popular tablets above. We could add a “color gamut” row to the chart, measuring against sRGB, which would look like this:

From this information, a shopper could gather that the Nexus 7 and Kindle Fire HD have about the same color performance and both outdo the iPad mini. That is an accurate assessment, but it’s not the whole story. If we look at those color gamuts plotted in CIE 1976, some important nuances become apparent.

By measuring the percent of sRGB, we know how much of that overall color standard the device can reproduce.  However, displays usually produce more of one color than another and that information is completely lost with this measurement.  The Nexus and Kindle have significantly deeper blue than the iPad mini, most likely due to a narrower blue color filter like the one found in the third and fourth generation iPad. This accounts for most of the difference in sRGB coverage between the iPad mini and the other two devices.

Take a look at the other two primaries and it gets more interesting. In the image on the right that zooms in on green, we see that the Kindle Fire has the deepest green of the three, followed by the iPad mini and the Nexus.

For reds, though, it’s different again, with the Nexus having the deepest reds followed by Kindle and then iPad.

If we ever want to make color performance a real differentiator in consumer choice, we need to develop a new universal standard to easily compare color across devices, taking into account all of these nuances.

Color is a complex story to tell, but small differences in color performance are just as noticeable to consumers as pixel density in everyday use. Next time you find yourself at a retailer who carries all three devices, try googling test patterns and look at the differences. You might be surprised.

Gizmodo: Tech’s New Most Meaningless Spec: PPI

source: Gizmodo

Adrian Covert of Gizmodo has an interesting piece looking at the gadget industry’s recent obsession with high PPI displays. With devices like the HTC DNA pushing resolution well past 300 PPI, electronics makers may be turning PPI into the next overhyped marketing stat, just like contrast ratio is for the TV industry and megapixel is for the digital camera.

Adrian gets to the heart of the problem:

There are plenty of ways to make a better-looking display. But we’ve reached the point in the pixel density wars where higher figures have stopped automatically equating to improved performance for users. Any grandstanding about pixel density, from here on out, now is mostly just marketing fluff.

We tend to agree, and color performance is probably the display feature with the most room to improve. The best LCD smartphones on the shelves right now can show you more pixels than your eye can detect, but can only show you about a third of the colors you can see. If electronics makers want impactful feature improvements for new devices, color performance is where it’s at.

iPad Content Creation gets more Colorful with FiftyThree’s Paper app

App developer FiftyThree recently updated one of my favorite creativity apps for iOS, Paper, with an impressive new color-related feature. If you are not familiar with Paper, it’s a sketchbook app capable of making the work of even non-artists like me look gallery worthy with an intuitive and responsive interface.

The new feature, which FiftyThree calls “the biggest leap forward in color controls in the past 40 years,” is a color mixer that allows you to create a wide array of colors within the app just as you would in real life. They say they put a lot of time and effort into making the new mixer feel natural. The Paper color mixer works just like finger painting as a kid, mixing yellow and blue in the Paper app mixer produces green.

The new color mixer, shown at the bottom of this screenshot, lets you mix multiple colors to achieve a much wider palette in the new version of Paper.

This is a great feature that expands the content creation capabilities of an already exceptional app. But, as great as this app is, it’s still limited by the color capability of the device it’s installed on. Even the latest iPad, which can produce 100% of the sRGB color gamut, still only shows about 1/3 of the visible color spectrum.

The experience you will have mixing and creating colors on today’s tablets just will not be nearly as dynamic or visceral as making a physical painting. Not until better, wide color gamut technology is adopted in displays will the digital color experience match the stunning world of color we live in.

Time to Ditch the Diagonal?

Size is a critical dimension for consumers to consider when buying a product with a display. Will this TV fit on my wall? Would this tablet fit in my jacket pocket?  How much picture am I getting? To guage displays today, we take a diagonal measurement of a 16:9 rectangle. This leaves value on the table. Not just because consumers are notoriously bad at math, it fails to capture the full value of the increase. As display industry analyst Bob Raikes said:

A display that has twice the diagonal (and the same aspect ratio) has four times the screen area. Would Intel describe the clock speed of its CPUs by giving them a number that is the square root of the clock speed? If Intel went from 1GHz to 2GHz, would the company really give customers a number that is just 40% bigger? Ah, we’ve gone from 1 IntelMark to 1.4 IntelMarks. No chance!

Why would we say “twice” when the real value increase is “four times”? This is especially relevant as consumers shop more online. Although size may be apparent in a brick and mortar showroom, it is not easily conveyed online. Take a look at this image- which tablet is bigger? By how much?

Apple’s Phil Schiller demonstrated this yesterday at the iPad mini announcement. The new iPad mini is only 0.9 inches or 12% bigger than a Nexus 7 on the diagonal, he says, but it is actually 35% larger by area. This is another example of display marketing efforts starting to move beyond PPI comparisons. Product and display marketers: let’s get real about the value we’re adding – whether it’s surface area or color. Let’s stop leaving value on the table.

Source: apple.com

The case for wide-gamut in your photography workflow, even if you are exporting to sRGB

This is a great, exhaustive tutorial on managing color gamut for photographers by color expert Andrew Rodney. He does a great job making the case for working in wide gamut color spaces like Pro Photo, especially when capturing in RAW. Using smaller gamuts like sRGB throws away useful color data that printers and more and more displays can recreate.

How does ink thickness change the appearance of printed color?

We typically focus on color as it relates to displays here at dot-color, but I came across a fascinating post about color in the print industry from John the Math Guy that I had to share. In this post, John takes a close look at how ink looks at different thicknesses and uncovers the reasons for some seemingly unconventional color-naming habits in the print industry.

What happens when we double the amount of ink on the paper? …it would seem that the thick layer of magenta is a lot closer to red. The plot below shows the actual spectra of two magenta patches, one at a larger ink film thickness than the other. The plot leads one to the same impression – that a thick layer of magenta is closer to red in hue than a thin layer.

Chart shows different spectrums of thick (red line) and thin (blue line) layers of magenta ink.

Read the whole thing here:  http://johnthemathguy.blogspot.com/2012/09/why-does-my-cyan-have-blues.html

 

DisplayDaily: Is quantum dot lifetime good enough for TV?

Ken Werner of Display Central has a post comparing the benefits of quantum dots to OLEDs in consumer TV applications.  Being the authority on quantum dot displays that we are here at Nanosys, Ken contacted us for an analysis.  Here is the explanation our Ph.Ds gave Ken:

OLEDs use organometalic compounds to emit light. They typically have a central metal atom surrounded by organic ligands. The decay issues are the same as with typical organic fluorophores.  In the excited state these molecules are very reactive to H2O and O2, as well as other small molecules that may be around. Once they react they become a different molecule and they will no longer fluoresce or phosphoresce and give off light. The more blue the light emission, the higher the energy of the excited state, and the more reactive the excited molecule will be. So your blue organic phosphores will have a much shorter lifetime than will red phosphores. The burn-in problem seen in OLED displays, that can be seen after just several weeks of operation with static content, is a manifestation of early blue degradation compared to green and red.

Conventional phosphores like YAG are doped materials. YAG used in white LEDs is actually cerium doped YAG. The cerium atom emits the yellow light and is surrounded by a vast amount of YAG. Quantum dots are similar in that a central core crystalline semiconductor material is used to confine the holes and electrons of the exciton (analogous to the cerium in YAG), and in our material this is surrounded by a thick shell of a different, lattice-matched semiconductor material (analogous to the YAG.) We call this a core-shell Quantum Dot structure. If the lifetime of our materials is less than that of conventional phosphors, it is typically because we have not made a perfectly lattice-matched shell, which may distort the core and cause defects at the core/shell interface that reduces the quantum yield.

The big difference here is that a perfectly made core-shell quantum dot does not have an intrinsic lifetime failure mechanism, whereas the organometallic compounds are intrinsically reactive to their environment, which makes them prone to shorter lifetimes especially at higher energies such as blue.

This is an important discussion, because TVs are a harsh environment for display components, running much hotter and brighter than tablets or mobile phones.  You can read the entire post here: http://www.display-central.com/flat-panel/is-quantum-dot-lifetime-good-enough-for-tv/

Updated: How does the iPhone 5’s color saturation measure up against Apple’s claims?

Commenter William thankfully double checked our math and we’ve corrected a small error in our % NTSC calculation.

We finally got our hands on an iPhone 5 yesterday. I tried asking Siri if she really has 44% more color saturation but she wouldn’t give up the goods, so I went with plan B and aimed our PR-655 spectroradiometer at the phone to find out just how impressive the screen really is. A lot has already been written about this display, but not much empirical evidence has been published about the color performance. How does the screen actually stack up to the marketing claims?

In short, Apple did an exceptional job improving color saturation and display quality in general, but the unit we measured just missed the 44% more color saturation claim.

Measuring Up

The iPhone 5 has significantly more color saturation than the 4S.

The 44% more color claim for the iPhone 5 is the same claim Apple made for the new iPad. As with the iPad, increasing the color performance of the iPhone 4S by 44% of NTSC 1953 gamut, measured using the CIE 1931 color space, would result in color saturation matching the sRGB color standard.  Using these standards as the goal posts, we measured the iPhone 5 at 70% of NTSC 1953 in CIE 1931, a 39% increase from the iPhone 4S, which measured at 50%. That’s 5% less of an improvement than Apple’s 44% claim and just 99% of sRGB (measured against the sRGB primaries).

While 5% less might seem like a big deal, getting to 99% of sRGB is a major feat and will result in tremendously noticeable color improvement in the phone. Additionally, color filters are notoriously difficult to manufacture. Slight variances in performance like this are common and most likely outside the range of a just noticeable difference for the average person.

If you want to know more about NTSC, CIE and sRGB, and why we are using standards from the 1930s, I have written extensively about this issue in the past.

How did they do it?

Much like they did with the new iPad, Apple significantly improved the color filter performance of the iPhone 5. Based on our experience, this type of improvement typically means that the display requires 20-30% more power to operate at the same brightness. Considering that the display is already a major source battery drain on the phone, this further underscores the engineering effort Apple made to keep battery life about the same as the 4S.

Let’s take a quick look at the changes in each of the red, green and blue color filters, starting with white, which is all three filters turned on:

Looking at the white spectrum of the iPhone 5, we see that the new color filters are very similar to those of the new iPad. Compared to the 4S, the peaks are slightly narrower, which improves color purity. In order to meet sRGB, they also moved to deeper reds and blues.

As with the new iPad, the biggest difference between the 4S and the 5 is in blue. Apple moved the peak to a deeper blue but, more importantly, they narrowed the filter so less green light leaks through. The green leakage causes blue to look a bit “aqua” on the 4S.

Retinal neuroscientist Bryan Jones looked at both displays under his stereo microscope earlier this week. His close-up shots really show off the difference in blue filters.

Apple again chose a slightly deeper wavelength of green which is less yellow and eliminated some of the blue leakage that had been muddying the green on the 4S.

The change here is subtle but as with the other filters, the peak is narrower, deeper in the red and leakage is reduced. One difference worth noting is that, while we are seeing less peak leakage in the red filter, there had been relatively broadband leakage across yellow, green and into blue that has been largely eliminated.

Conclusion

In all, it’s an exceptionally well-calibrated and accurate display for any kind of device, especially a smartphone. Apple has gone to great lengths to design a screen that brings the vibrancy of sRGB to the palm of your hand.
If you are not familiar with color filters or the inner-workings of LCDs in general this great live teardown by Bill Hammack is well worth watching: http://youtu.be/jiejNAUwcQ8