by Tim Brookes
High-dynamic-range (HDR) video is taking off in a big way. Some of your favorite movies are already available with enhanced color and brightness, and look even better than they did in their original theatrical releases.
But some remasters have caused critics to cry foul, igniting a debate around technical capability and artistic intent.
What Are the Benefits of HDR?
Before we consider whether the term “fake HDR” is even warranted, it’s important to understand what HDR video is. As its name implies, high-dynamic-range video has an increased dynamic range compared to standard-dynamic-range (SDR) content.
Dynamic range is the amount of information visible in an image or video between the brightest highlights and the deepest shadows. Modern HDR video is delivered in 10-bits per channel, as opposed to the eight-bits per channel in SDR. This means SDR can display 256 shades of red, but HDR can display 1,024.
This means more color information is visible on-screen, which is closer to what we would see in real life. More shades of a particular color also makes unsightly “banding” in gradients less prominent. The difference is most visible in fine details, like clouds or areas with subtle color variations.
HDR also adds luminance or peak brightness. The vast majority of HDR-capable TVs come with the basic HDR10 standard built-in. It stipulates that content be mastered at 1,000 nits, as opposed to the traditional 100 nits (recently revised to around 200) for standard-definition content.
This means bright objects, like the sun, a flashlight, or gunfire, can really pop when viewed on an HDR-capable display. The additional brightness makes elements like these look much closer to how they would in real life, creating a more immersive viewing experience.
HDR video is something you have to see to truly appreciate, but its improvement over SDR can be vast.
What Is “Fake HDR”?
The term “Fake HDR” has been thrown around YouTube, Reddit, and other platforms in the wake of a few high-profile Blu-ray releases. It refers to the reluctance of studios to grade their HDR productions to sufficient peak brightness and make the images pop.
According to Vincent Teoh, a professional display calibrator and reviewer, the 4K Blu-ray of Star Wars: The Last Jedi hits a maximum peak brightness of 250 nits, with the sun being graded at only 200.
Teoh also found that the Blade Runner 2049 4K Blu-ray barely rises above 200 nits, making it “an SDR movie in an HDR container.”
These HDR releases use a 10-bit (12 in some instances) color depth. This means they still deliver a better-quality image than SDR. However, because they lack the flashes of peak brightness shown in many other productions, some perceive these releases as “fake HDR.”
As another reference, a super-bright LCD, like the Vizio P-Series Quantum X, can hit a peak brightness of well over 2,000 nits. Even LG’s relatively “dim” OLED panels manage around 700 nits. Some reviewers and Blu-ray collectors feel these “fake HDR” releases have been hamstrung by underwhelming peak brightness.
This doesn’t mean a film looks bad; the image just doesn’t “leap off” the screen as it does in other releases. As these are major releases from some of Hollywood’s biggest studios, it’s clear that colorists and directors know exactly what they’re doing. The reluctance to splash out on HDR effects is intentional.