Well, we’re about to see more, a whole lot more – in fact, four times (4X) more – than what we can see now on the best HD screens.
Today’s screens tickle our retinas with two million pixels. Tomorrow’s 4k screens will blast 8.3 million pixels. Pixels so sharp and so clear, you’ll think you could walk into the display.
The name “4k” has already taken hold in our supersophisticated vocabulary; and we like things short and easy to say. However, last October, the Consumer Electronics Association (CEA) unanimously agreed on the term “ultra high definition” because they like bigger names. They’ll let you shorten it to “ultra HD.” Sony, however, said thanks but no thanks: We’ll call ours “4k UHD.” You and I will call them “4k.” The term “4k” is a slight exaggeration. The resolution is actually 3840 × 2160 (8.3 megapixels). But the “4” in 4K is the key because a 4k display shows four times as many pixels as an HD display, so you go from 2 to 8.3 megapixels (Mpix).
Transitioning to 4k moves everything up. The new displays, whether for computer monitors, TVs, or signage, are not going to be small. A “small” 4k display will be 31 inches (there is a Japanese-made, nine-inch 4k display, and LGD will launch 23.8-inch 4k LCD monitor panels shortly). The data rates to feed these monsters at 120 hz is enormous: at 120 hz, you have a gigahertz pixel rate. That’s not a problem for today’s GPUs – even a smartphone can drive a 4k screen. But, the input to 4k screens is HDMI, and the current version, HDMI 1.4b, can only support 4k at 30 hz. We should start seeing the first 4k displays running at 60/120 hz next year with HDMI 2.0.
Think of putting three 4k screens of up to 50 inches on three adjacent walls, with their bezels touching, to create a CAVE. I’m really excited about the prospects of 4k for a CAVE and other advanced visualization systems. Imagine, if you will, playing Stalker or Metro 2033 in an immersive 130-inch wraparound (88 inches per side), 24.8 Mpix (3 x 3,840 x 2,160) environment. Now, imagine doing it in stereo 3D. Far-fetched? In 2013, maybe. In 2015, for companies and universities – totally believable.
4k displays will be available from 31 inches to 85 inches or larger. Display Expert Bob Raikes of research firm Meko contends that for LCD makers, 4k at larger sizes is basically free “once they have solved remaining yield issues.” He adds, “Fundamentally, an 84-inch [screen] costs them little more than four 42-inch full HD. A 55-inch costs little more than four 27-inch HD monitor panels. There’s a bit more processing and some more driver chips, but only a little more.”
However, Raymond Soneira of DisplayMate Technologies, thinks it is visually pointless to get a 4k display that is only 50 inches, because with 20/20 vision, you would need to watch from 39 inches (or less) to resolve the 4k pixels (www.displaymate.com/news.html#7). Since almost no one (in the US) has a living room TV with a viewing distance of less than seven feet, an 80-inch diagonal is about the smallest 4k TV that makes visual sense. At SID, both LG and Samsung showed 84- to 85-inch 4k TVs. But Soneira agrees that it is a bit different when there is digitally generated fine text and graphics rather than TV, video, and photographic images because the eye can visually detect more subtle differences with precise pixel layouts and structures. And with computer monitors and multimedia displays, people are more likely to move or walk up to the displays to more closely examine and even study the image content.
Content is Key
The other issue usually brought up when discussing 4k is, where is the content? The answer seems to rest with the Blu-ray Disc Association (BDA). The BDA, as part of its ongoing responsibility to maintain Blu-ray Disc as the premium platform for watching movies and other content at home, established a task force last year to study a range of possible format extensions, including those that potentially enable 4k content playback on Blu-ray. Through the first quarter of this year, the task force solicited and received numerous proposals, and is now evaluating the various technologies.
To that end, Mark Fihn, publisher of Veritas et Visus, contends Blu-ray 4k will come faster than the original Blu-ray, for several reasons:
- The BDA will do everything possible to avoid another format war, as they did with HD-DVD. If the BDA doesn’t implement a 4k standard soon, it runs the risk of an expensive format war. That could still happen if the China market adopts 4k quickly, as many expect.
- Blu-ray technology now allows the added storage capacity necessary to support 4k. This was a bit uncertain when Blu-ray was originally proposed.
- 4k TVs exist today, and will come quickly. When Blu-ray was originally released, most HDTVs were 720p, not yet supporting 1080p.
- 3D looks much better at 4k levels, stirring additional demand for 4k Blu-ray.
Fihn says, “Bottom line, there’s no sense about debating ‘if’ – it’s just a question of ‘when,’ and I believe it will be quicker than most analysts are currently predicting.”
RELATIVE SCREEN resolutions (assuming the same physical-size pixel).
More and More Color
The other issue prompting discussion with 4k displays is the color range, or gamut. Several of the 4k displays are publishing a specification of 1.07 billion colors. It’s difficult to find the color standard the 4K displays are supporting. Michael James, president of Portrait Displays and an expert on color, comments, “Although there is no certainty with standards, the film and video content is captured and archived in DCI-P3 color space, which contains the widest gamut of all of the emulated color spaces. The REC2020 standard, which specifies two resolutions, both with a 16:9 aspect ratio: 3,840 x 2,160 (what everyone calls ‘4k’) and 7,680 x 4,320 (‘8k’), has a color gamut beyond what current technology can achieve with emissive displays. Neither OLED or Quantum Dots (QD) can hit the RGB points called for. And from a sales perspective, color will trump resolution in the showroom. Resolution is distance-dependent, color is not. Saturated colors appeal across the showroom floor.”
James notes that this was demonstrated at SID, where the QD displays used red to show the difference that an expanded color gamut makes. “The problem with DCI-P3 is the technology required to reach the color gamut,” he says. “The only systems we have seen that can show a DCI-P3 color gamut are RGB backlights, QD, or OLEDs.”
According to Soneira, the frequently advertised number of displayed colors is a specification designed to intentionally mislead consumers into thinking that the display has a large gamut. “It is actually just the number of possible displayed intensity combinations, and is just the bit-depth cubed, which is 1.07 billion for 10 bits,” he says. “Those 10 bits may be just the final display register. Other than CRTs, I’ve never seen a display actually deliver a visual 8 bits on the screen (because intensity irregularities are larger than the least-significant bit).”
Soneira has an article in the next issue of SID Information Display Magazine on how the display color gamut and image contrast vary in ambient lighting (rather than the dark), and how to automatically compensate for it dynamically. (See Soneira’s article, “Understanding Misleading Display Specs,” at www.displaymate.com/news.html#9.)
Lately, there are issues surrounding the pixels themselves. A 50-inch screen will have pixels that are 0.023 inches – that’s almost a thirty-second of an inch and easily visible if you get close. Therefore, I think content creators are going to have to take a little added care and employ higher super-sampling techniques to avoid artifacts.
So, what comes after 4k? Why 8k, of course: 8k UHDTV (4320p) has a resolution of 7,680 × 4,320 (33.2 Mpix), 16 times the pixels of current 1080p HDTV, which brings it closer to the detail level of 15/70mm IMAX. NHK of Japan advocates the 8k UHDTV format with 22.2 surround sound as Super Hi-Vision.
In April 2012, NHK (in collaboration with Panasonic) announced a 145-inch (370cm) display (7,680 × 4,320 at 60 fps), which has 33.2 million 0.417mm square pixels.
No doubt about it, 4k is coming like a freight train, and it’s going to get here sooner than most people realize – much faster than HD did. Why? There’s a combination of reasons. First, the panel makers can. Second, they have to pump out a lot of big screens to get the ROI on the huge fabs they built over the past five years. And third, the industry and, hopefully, the consumers are ready for the next great thing.
But if 4k screens are going to be big, 80 inches or more, will 8k require much bigger houses? Maybe for some, but most likely those will be reserved for theaters and science.
Lastly, there is the issue of vision. 20/20 is an average, not a limit. Those with good vision can resolve 20/10. Even if a person can’t resolve an eye chart, Japanese research shows improvements in “apparent reality” at 2.5 times the resolution of 20/10 – five times the resolution of 20/20.
So get ready to “see” the present and the future.
Jon Peddie is president of Jon Peddie Research, a Tiburon, CA-based consultancy specializing in graphics and multimedia that also publishes JPR’s “TechWatch.” He can be reached at firstname.lastname@example.org.