HDR Performance

Moving on to performance which I’m sure a lot of you will be interested in, and there’s quite a lot to say here considering there are so many features packed in. Let’s tackle HDR first before moving on to color performance and response times.

Looking at brightness support we have 1000 nits of peak brightness and 600 nits of sustained brightness, which is well above what is required. I measured full white sustained brightness of 634 nits which is absolutely eye scorching in regular viewing conditions, and that gradually increases to nearly 700 nits for a 25% window, and 900 nits for 10% windows or smaller.

I achieved an impressive sustained brightness of 933 nits for a 2% window, with flashes pushing well over 1,100 nits, meeting Asus’ specification claims. The display can also produce a full white image for around 1 second at 1,000 nits, which basically requires sunglasses to view.

For local dimming we have a 384-zone full array backlight, so at this monitor size each dimming zone covers roughly 22 x 26 mm. The backlight is extremely responsive, adjusting its light output in under 10ms in worst-case transitions, which is like a 1 frame delay at 98 Hz. As the backlight is so responsive, there’s no visible ‘afterglow’ when a bright object suddenly disappears from view, and the zones are small enough that HDR glow around bright elements is minimal and not really noticeable in most typical conditions like gaming or watching movies.

The only time I noticed the ‘glow’ effect was when the panel tried to show small white text on an otherwise completely black screen, and that’s not something that happened often. In actual games, the dynamic range between a flickering fire and the darkness of night was massive and that’s where the FALD backlight really shines in its ability to simultaneously display 1000 nits in some areas, and just 0.02 nits in others. The very high contrast ratio this type of backlight provides, and brightness levels way above regular SDR screens, is the key reason HDR looks incredible when done properly, and the PG27UQ is one such display that does HDR well.

In terms of contrast ratio measurements, I achieved 53,000:1 at peak, though that falls to 33,000:1 when judging based on the monitor’s sustained brightness output. When disabling the dynamic backlight the monitor is just a typical IPS in terms of contrast with a ratio just above 1,000:1, but really I see no reason to disable the dynamic backlight unless you are viewing something where the glow issue is very noticeable. For the vast majority of users and the vast majority of content you’ll be viewing, even in the SDR mode, leaving the FALD zones active is the way to go.

You can also adjust the speed of the FALD backlight just in case the default ‘fast’ mode is too fast for you. There might be some occasions where rapid changes to backlight brightness aren’t ideal for the content you’re viewing, in which case the slower modes will be better for you. However, there wasn’t a single time where I felt the fast mode was too fast, especially while gaming, so again I don’t think this is a setting you’ll want to change.

The final things on the HDR checklist are color space: the PG27UQ supports 97% DCI-P3 coverage which is much wider than sRGB, and the usual stuff like 10-bit processing and an 8-bit+FRC panel. In my testing I actually achieved 93% DCI-P3 coverage but that’s still pretty good and above what is required for HDR.

I’m not going to show color accuracy results for DCI-P3 because I’ve been informed by several people that the testing tools I have available to me aren’t accurate enough to test this type of monitor in wide gamut. Some tools can do it, but not what I currently have or what is available in our budget, so I’m not going to show inaccurate results and instead skip wide gamut accuracy. However I will mention there is a mode to use wide gamut with SDR, so content creators working with DCI-P3 in an app that doesn’t natively support HDR can still make use of this monitor’s support for that color space.

Now is probably a good time for just some general thoughts on HDR. The PG27UQ is quite clearly the best HDR monitor I’ve used, the contrast and brightness specs illustrate this on paper but when you actually get to using the monitor, it’s far and away superior to a regular SDR monitor in games that support HDR properly. Even SDR content gets a handy boost from the FALD backlight, because this LCD has a contrast ratio far higher than regular LCDs in the SDR mode.

In games like Far Cry 5 that support HDR really well, you’re not only getting a more vibrant image as the panel can actually display more colors, but there’s so much more detail visible particularly in high-contrast scenes. Take an outdoor sunny scene with heavy shadowing. This monitor has the ability to dazzle you with a sun burning at 1000 nits, while simultaneously providing plenty of visible detail in a dark shadowy area. Neither of these elements are blown out, because the monitor’s dynamic range far exceeds a regular SDR display, and it more closely simulates how the scene would look in real life.

It won’t come as a surprise that it’s very hard to demonstrate on camera exactly how different this monitor looks, it’s just one of those things you have to view yourself to see the difference between HDR and SDR. But unlike several other monitors with weak HDR support, the PG27UQ gets it right and the result is a fantastic HDR image that blows boring old SDR away.