Explained: What Is HDR or High-Dynamic Range Mean?

March 16, 2020 Topic: Technology Blog Brand: The Buzz Tags: HDRHDTVHigh-Dynamic RangeTechnologyTV4K8K

Explained: What Is HDR or High-Dynamic Range Mean?

If you are in the market for a new television, then you’ve likely been regaled with the wonders of the latest must-have TV feature: HDR, or high-dynamic range. But how exactly does HDR technology work? Is it as revolutionary as the TV industry claims, or just a branding ploy?

If you are in the market for a new television, then you’ve likely been regaled with the wonders of the latest must-have TV feature: HDR, or high-dynamic range. But how exactly does HDR technology work? Is it as revolutionary as the TV industry claims, or just a branding ploy?

 

The idea of contrast is crucial to understanding the problem that HDR is trying to address. Contrast is simply the difference between the brightest white and the darkest black that your TV is able to show. In TV hardware parlance, contrast is commonly measured as a ratio; for example, a contrast ratio of 1,000,000:1 means that your TV is capable of showing a color that’s up to 1,000,000 brighter than its darkest color. The higher your TV’s contrast ratio, the greater the range of colors that you can see--deep blacks, vibrant whites, and everything in between. It’s difficult to understate just how indispensable a good contrast ratio is for a truly immersive viewing experience. In fact, there is a mountain of research to confirm that contrast ratio has a bigger impact on image quality than resolution.

This gets us to the root of the problem: the standard-definition range (SDR) content that we’ve consumed for most of our lives lacks the contrast levels necessary to accurately reproduce all of the vibrant colors perceptible to the human eye. Consider the palette of a sunset, gently transitioning from dark violet all the way to bright orange—the depth and richness of that transition is lost on a standard TV display.

This is where HDR technology comes in, dramatically upping display brightness to enable a wider color range. SDR TV’s typically sit at a brightness of around 400 nits (units of brightness), whereas top-end HDR displays can go all the way up 10,000 nits. Rather than relying solely on the brute strength of high brightness to reproduce a more realistic color range, most HDR TV’s are also paired with Adobe’s  Wide Color Gamut expanded color space.

Nearly all current mid and high-end TV’s are HDR-compatible, but not all HDR TV’s are equal. For starters, there are several different HDR formats; HDR10 is by far the most common and least demanding, with a maximum brightness of 1,000 nits and 10-bit color depth. HDR10+ raises the bar with a maximum brightness of 4,000 nits and more sophisticated data processing protocols. Finally, Dolby Vision is a proprietary derivative that allows for up to 10,000 nits and introduces dynamic data processing. The technical minutiae and industry politics of these competing HDR formats is a topic of its own, but the bottom line is that there is no “wrong” choice for consumers. Not only do most high-end 4K TV’s support more than one HDR format, but the differences between HDR10+ and Dolby Vision are far too miniscule to inform your buying decision over more salient factors like display panel type, resolution, and screen size.

Whereas some high-end TV features, such as OLED panels or 8K resolution, are locked away behind steep paywalls, the barrier of entry to HDR technology is lower than ever. In 2020, it’s perfectly possible to buy a large, 4K HDR TV in the sub $500 category. Much more so than the cost of entry, the biggest obstacle to the mass consumption of HDR content is, simply, the lack of HDR content. HDR-friendly services like Netflix, Amazon Prime Video, and Apple TV+ remain your best bet of putting your new HDR TV to good use, but the overall pool of available HDR content is sparse for the time being.

Mark Episkopos is a frequent contributor to The National Interest and serves as a research assistant at the Center for the National Interest. Mark is also a PhD student in History at American University.