One of the most impressive demos at CES 2018 was the 85″ Sony 10,000-nit display. It was billed as the “X1 Ultimate Full-Spec HDR 8K Display,” referring to its use of Sony’s prototype X1 Ultimate video processor, 8K resolution, and “full-spec HDR.”
As many of you know, three of the major high dynamic-range (HDR) formats are HDR10, HDR10+, and Dolby Vision. All three are based on the EOTF (electro-optical transfer function) called PQ (Perceptual Quantization), aka SMPTE ST 2084. The EOTF defines how different brightness values in the video signal should be converted to luminance levels from the display.
Unlike the EOTF that has been used for decades—which is called gamma—PQ is based on absolute luminance levels, which are measured in units called nits. (The more technical term is candelas per meter squared, but most folks use nits for simplicity.) In Dolby’s initial research into HDR, a luminance level of 10,000 nits was determined to be the maximum that most people could tolerate comfortably. And because there were no displays that could come anywhere close to producing 10,000 nits—other than the custom rig that focused the light output from a DCI projector onto a 24″ screen for Dolby’s research—it seemed to leave a lot of room for growth in future displays.
That remains true today, though if this demo is any indication, a true 10,000-nit display might become available sooner than expected. The Sony 10,000-nit display demonstrated what “full-spec HDR”—that is, luminance levels that reach the maximum defined by PQ—looks like. It’s not a product that will be released this year or, presumably, next. This was a technology demo that illustrated what HDR could look like if its maximum capabilities are utilized.
It’s important to understand that this display—and just about any HDR display—can reach its peak luminance only in small sections of the screen. It cannot pump out 10,000 nits from a full-screen 100% white field, which would be truly blinding. The peak luminance of any HDR display is used to beef up specular highlights—things like pinpoint reflections of the sun from chrome, or the sun itself if it’s in the image.
The ability to reach very high luminance levels in specular highlights makes the image look more like real life, even more dimensional. But even 10,000 nits isn’t high enough to match what we see in the world around us. Reflections of the sun in chrome are much higher than 10,000 nits, and the sun itself is over 1 billion nits! Still, the higher the luminance of specular highlights, the more realistic the image looks.
That was clearly demonstrated by the Sony 10,000-nit display at CES 2018. The prototype screen was placed next to a Sony Z9D, the company’s current flagship LCD TV that is capable of reaching close to 2000 nits. The prototype’s image was obviously brighter overall, and the specular highlights were way brighter, making the Z9D look positively dull by comparison. Of course, my camera couldn’t capture the full dynamic range of the image, but the photo at the top of this article includes several specular highlights that really popped in person.
I heard several people say it was too bright, especially in the blacked-out area in which Sony placed it. I didn’t think it was too bright; in fact, I thought it was like looking out a window. During the transition from SD to HD, I remember hearing that HD was like looking out a window, but it was nothing compared to this!
According to Sony, the prototype X1 Ultimate processor is required to control the 85” 8K display up to 10,000 nits. I assume the panel uses the company’s Backlight Master Drive technology, in which the brightness of each LED is individually controlled. This technology is also used in the Z9D, but not to this extreme. However, Sony would not reveal how many LEDs/zones were implemented in the prototype.
The X1 Ultimate processor also handles 8K. According to the signage next to the Sony 10,000-nit display, “The X1 Ultimate processor intelligently detects and analyzes the immense amounts of data in 8K signals, then enhances detail even further with the specific, 8K-optimized, object-based Super Resolution.”
I’m not sure what some of that really means; for example, why would you need detail enhancement at 8K? Maybe it refers to detail enhancement when upscaling lower resolutions to 8K. Also, I do understand the value of object-based image analysis, and the X1 Ultimate is said to be able to identify more objects in an image than ever before.
The demo was so impressive, we had to give it an AVS Forum Best of CES 2018 award. Philip Jones, Product Technology Manager, accepted the award on behalf of Sony.
The Sony 10,000-nit display produced an astounding image, showing the world what “full-spec HDR” looks like. Bravo, Sony!
Check out my interview with Philips Jones, who talks about the Sony 10,000-nit display, X1 Ultimate processor, A8F OLED, and X900F LCD TVs: