HDR Monitors

PC monitor manufacturers tend to focus on a particular buzzword or acronym almost every year. In the past, we have been treated to HD (high definition), denoting the screen is capable of running a minimum 720p resolution. 3D came and went, UHD (ultra-high definition), also known as 4K, is now very much in vogue on larger screens. Another popular one recently is HDR, or high dynamic range. In this TekSpek we explain what HDR is and then compare the various standards so that you can make the most-informed purchasing decision.

What is HDR ?

HDR aims to improve the image quality of PC monitors by increasing the overall brightness, enabling a more noticeable colour gamut, and having, as the name intimates, a bigger dynamic range between whites and blacks. Put simply, a good HDR interpretation makes videos and games look far more lifelike and more closely mimics the light spectrum a human eye perceives. There is significantly more 'pop' in a quality HDR picture than on standard.

The primary part of the HDR jigsaw is brightness. Most non-HDR sets, typically budget offerings output a maximum brightness of around 250 nits, where a single nit is defined as the intensity of one candela per square metre. This is why you may see this figure reported as cd/m².

Yet brightness remains a single facet of HDR. Another is the ability to produce extreme brightness and near-darkness in the same scene. Imagine a night time video where a super-bright street lamp illuminates our protagonist. The lamp's light range only goes so far, covering our hero's face and body, though much of the scene's periphery remains in either in shadow or darkness. A high-quality HDR set is able to concurrently show these two ends of the spectrum without compromise. The luminance difference between the whitest whites and deepest blacks is known as the contrast ratio, and the higher the better. A quality panel is able to produce a 20,000:1 ratio, which means the peak whites are 20,000 times brighter than the deepest blacks. Of course, in an ideal world, you would want an infinite contrast ratio.

The Apple Pro Display XDR - arguably the finest monitor screen around

Lastly, a decent HDR set ought to be able to produce a massive array of colours on top of extreme brightness and great contrast. A typical 8-bit panel is able to produce a potential 16,777,216 colours, or 256 shades each for the red, green and blue values. This has been the colour standard for some time. True 10-bit panels are able to produce 1,024 shades of each primary colour, meaning a total of over a billion displayable colours (1,073,741,824). This 64x enlargement of 8-bit is most keenly felt in scenes where there is a very gradual colour shift - a lovely sunset, for example.

Some HDR monitors use a method called 8-bit plus frame-rate control (FRC). By using a cheaper 8-bit panel and then employing a dithering algorithm - the FRC bit - to blend the colour of adjacent pixels, these sets artificially raise the number of viewable colours. Full-on 10-bit is always better than 8-bit plus FRC, which is better than 8-bit.

Okay, so HDR requires a super-bright screen, great contrast ratio, and enough colour depth for seamless gradient changes. All monitors exhibit these features to some degree, but the better ones are advertised as HDR. The next logical question is what constitutes HDR, how does the PC gamer or studio creator choose the right level of HDR, and what are the differences between them? Let's take each in turn. DisplayHDR overview

Unlike televisions which also tout various levels of HDR and have a confusing array of competing standards, PC monitor manufacturers mercifully adhere to one standard called DisplayHDR run by the Vesa organisation. It has a number of DisplayHDR performance levels that range from 400 to 1600.

DisplayHDR 400

This is the entry-level specification offering the most basic of HDR experiences, and the majority of monitors fall into this category. Achieving this standard requires the screen to have true 8-bit image quality, global dimming, a peak luminance of 400 cd/m2 - hence the name - and minimum guidelines for colour and gamut that are superior to the non-HDR monitors.

Truth be told, the video and gaming HDR experience at this entry level is lacking in punch and effect. There's a marginal difference between a regular SDR monitor, but the experience is not immersive enough for one to sit up and take notice. It can be argued that HDR400 does not put the bar high enough.

DisplayHDR 500

SCAN believes that enthusiasts and gamers need to set the HDR500 standard as their entry into the high-dynamic space. The peak brightness is 25 per cent higher across monitors and laptop screens, which starts to make a perceivable difference in impact. More so than just the greater luminance, the colour gamuts and black depths are of a higher standard. Screens need to have local dimming in place - where you can turn portions completely off - and have the capability to process 10-bit, as we spoke about above. These solid improvements ought to constitute the basics of HDR for everyone.

DisplayHDR 600

Building on HDR500, getting 600 nits of brightness starts to liven everything up. We'd recommend this level as the starting point for the well-heeled enthusiast. Samsung, Dell, HP, LG, MSI, Philips, AOC and Asus all have models that play in this area. They start at 27in and rise to a massive 49in.

DisplayHDR 1000

This is where the real quality starts. 1,000 nits of brightness is immediately recognisable to anyone coming from a budget monitor, made possible by full-screen local dimming. One is looking at the best of each manufacturer's gaming range, so the Acer Predator, Asus ROG Swift, or HP Omen.

DisplayHDR 1400

Getting near the best. Offering a staggering amount of visual oomph along with a dynamic contrast 3.5x higher than even HDR1000, this ultimate standard also introduces the highest colour gamut of 95 per cent of DCI-P3 65. So not only is the image quality extremely accurate and full of incredible variations in colour, it carries the highest amount of pop available. Truly excellent screens for the discerning gamer and content creator. Only a trio of screens make this grade, ostensibly for the content creator.

DisplayHDR 1600

Creme de la creme. This one is for content creators only. The Apple Pro Display XDR crams an incredible 6,016x3,384 resolution into a 31.5in panel while the Asus PA32UCG runs with a more conservative 3,840x2,160 resolution inside its 32in casing. Primed for photographers and video guys who demand the absolute best, be prepared to pay handsomely for owning either.

Wrap

HDR is here to stay, and once you see it, going back to an SDR screen is difficult. The Vesa group makes it easy for gamers and enthusiasts to compare monitor HDR implementations by releasing the DisplayHDR standard comprised of multiple performance tiers.

SCAN recommends customers look towards DisplayHDR 600 as a minimum for a good high-dynamic range experience in games and video content from the likes of Netflix or Amazon Prime. The next real step up is DisplayHDR 1400, offering much-improved colour gamut and wonderful contrast and brightness. Should funds allow, the very best screens are currently able to produce 1,600 nits of brightness, soon to be followed by 2,000-nit panels.

The future is bright, the future is HDR. See our range of 4K / HDR monitors.