Upgrading to an Ultra HD TV: Here’s What You Should Know

• Minimum resolution of 3840 X 2160 (aka UHD)
• Inputs must accept a BT.2020 colour representation
• 10 bit colour depth ( more than 1 billion colours)
• Must be able to display more than 90% of the DCI-P3 colour gamut
• Must comply with the SMPTE ST2084 EOTF High Dynamic Range (HDR) spec
• Display must be capable of at least 0.05 to more than 1000 nits of light output (20,000:1 contrast ratio) OR
• It must be capable of a least .0005 to more than 540 nits of light output (1,080,000:1 contrast ratio)

   From these specs we can see that the Digital Cinema Initiatives (DCI) 4K resolution of 4096 × 2160 used in Sony’s 4K projectors would also qualify as it exceeds UHD’s 3840 X 2160 resolution. The required colour palette is far broader than the 8 bit colour we’re used to with Blu-ray players, which are only capable of 16,777,216 colours. This may sound like a lot, but is actually 64 times less than the UltraHD Premium standard. The recently released UHD Blu-ray players also support the same 10 bit colour gamut.

The two different contrast ratios are tailored to different display technologies. The first one is primarily aimed at LCD-based displays, while the second is aimed at OLED displays. The far wider contrast ratios associated with OLED clearly suggests that this technology is capable of fabulous blacks and awesome dynamic range. The LCD-based sets, with their greater output, would perform a little better in rooms with poor light control but if you’re looking for the best possible performance in a darkened room, the OLED wins hands down.

So now you’re all set right? Not so fast. Although the UHD Alliance’s efforts to make things simple and easy are commendable, there are some noteworthy issues. Sony, for example, who is one of the alliance’s big members has chosen not to use the UltraHD Premium logo for its own products. Instead, it uses its own internal standard called “4K HDR” even though their products do comply with UltraHD Premium specifications. Samsung and Panasonic, on the other hand, have embraced the new logo.

The bigger issue is VIZIO. They don’t agree at all with the new standard, sighting that the specification lacks important details on exactly how to measure various display characteristics like light output, peak brightness and contrast ratio. They claim that there are no set limits for undesirable phenomena, such as haloing artifacts and blooming, which adversely affect dynamic range and picture quality. This could lead to the certification of displays that really don’t deserve it or the omission of sets that do. This is clearly not a desirable situation.

VIZIO even accused the UHD Alliance of creating specifications that favour certain hardware platforms to the detriment of others. For example, VIZIO’s reference series sets are spectacular performers but don’t technically meet the UltraHD Premium spec. Their contrast ratios are 800,000:1 which is phenomenal but they don’t fall neatly into either of UltraHD Premium’s two contrast ratio categories. As a result, VIZIO has chosen to pursue a competing HDR spec called Dolby Vision. They feel that Dolby Vision is a superior and more robust specification. It’s a little ironic that Dolby is also a member of the UHD Alliance.

Dolby Vision is indeed superior to HDR10 in several ways. For example, Dolby Vision sets its current brightness target at 4,000 nits with a contrast ratio of 2,000,000:1. In the future, the brightness target will increase to 10,000 nits. Furthermore, Dolby Vision allows a colour depth of up to 12 bits which represents more than 68.7 billion colours. Finally, Dolby’s technology also allows contrast ratio optimization from scene to scene within a movie whereas HDR10’s tweaks are applied across the entire film.

In addition to VIZIO, LG, Sharp, TCL and Philips are also pursuing the Dolby Vision spec on at least some of their models. Studios like 20th Century Fox, Paramount, Sony Pictures, Disney and Warner Brothers have also announced support for Dolby’s format. So unlike VIZIO, some manufacturers and studios have clearly chosen to embrace both technologies.

Unfortunately, it looks like we may be heading toward a minor HDR format war. On the bright side, both can coexist peacefully. In the future, we may be seeing TVs, UHD Blu-rays and players sporting both logos. For the moment, UltraHD Premium has greater market penetration but who knows what will happen in the long term. Regardless of which option you choose, both will have very real benefits. And those zombies will look better than ever.