HDR Grayscale, EOTF & Color
To run HDR benchmarks, we add an HD Fury Integral to the signal chain to simulate HDR10 content from our Accupel DVG-5000 pattern generator. This enables us to measure the PG27U’s grayscale in five percent increments, EOTF (electro-optical transfer function, for turning digital code into ligt) tracking and color gamut capabilities within a Rec.2020 container.
Grayscale Tracking & EOTF
We measured both full-field and 10 percent window patterns and found the latter to offer better accuracy. Grayscale was essentially perfect from bottom to top with only a slight shift to blue in the mid-tones. The elevated errors were caused by a slight rise in the EOTF near the clipping point. This is not visible to the naked eye. The PG27U has the most accurate HDR grayscale and luminance tracking we’ve measured yet.
Color Gamuts Within Rec.2020
Most HDR displays take a somewhat interpretive approach to color tracking to make the gamut seem as large and vivid as possible. The PG27U stays fairly close the mark but bumps up saturation a bit. While this isn’t strictly accurate, it is closer than any other HDR monitor we’ve tested. All color points were within sight of their targets regardless of the base gamut. It even came shockingly close to the outer limits of the Rec.2020 triangle. If you want to see what extended color is all about, this monitor is a definitive example.
Ultra HD Blu-rays
We want to be clear that the PG27U is not just a gaming monitor. It can do everything well, and that includes watching video. Hooking up our Philips BDP-7501 Ultra HD Blu-ray player revealed that it is a perfect display for watching the latest hi-res content in HDR. It handled 24p film cadences correctly, so there was no stuttering like that seen on monitors that convert this material to 60p. It also switches automatically into HDR mode when necessary without user intervention. If you find the picture too bright, go into the Color menu and reduce the Reference White slider. It’s normally fixed at 80 nits, which is fine for most content.
Planet Earth II is a reference-level demo for any Ultra HD display. I’ve watched it on at least 20 different projectors, monitors and televisions, and none can compare to the PG27U. The extra color was evident in blue skies, deep red highlights, and the rich green of trees and vegetation. Detail was made even more impressive by superb contrast afforded by that full-array backlight. I looked for the halo effect which is a characteristic of multi-zone units and saw it occasionally in the opening of the “Cities” episode, but starfields did not produce the artifact. In this regard, it is superior to the Dell UP2718Q.
To check out shadow detail and black levels, I watched A Quiet Place, which is full of dark material. Blacks are truly black on this monitor, and I mean plasma-level black. It’s the first LCD I’ve seen that can go toe-to-toe with my reference Pioneer Elite TV. HDR has truly brought back the amazing dynamic range we enjoyed in the CRT era. There are many displays that feature HDR and extended color, but I’ve seen none that implement it as well as the PG27U.
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