20180420 - Objective 2017/2018 PC Display Discussion


"HDR" Label on PC Displays Does Not Mean High Dynamic Range
PC displays are effectively all LCD displays now. LCD panel technology with regards to real contrast ratio (aka Dynamic Range) has not really changed for at least half a decade. Take a look at the TFT Central Monitor Panel Part Database which lists contrast ratios for the panels which are and have been available for LCD displays. Here is a rough breakdown of options,


An example of a real high-dynamic-range display is the Panasonic ZT60 TC-P65ZT60 (2013 Plasma HDTV). See Sound and Vision Review for measured data. Still a great choice for HDR mastering as no LCD can get close to the dynamic range of this plasma panel.


An example of the best possible PC LCD high-dynamic-range display is the Eizo Foris FG2421 (2013 Gaming Display). See TFT Central Review for measured data. This is a good "HDR" display because the OEM decided to use one of the best LCD panels.


An example of a modern PC display labeled for "HDR" is the Samsung C32HG70 (2018 FreeSync 2 HDR Gaming Display). See TFT Central Review for measured data. Notice this is less bright and has less dynamic range than the 2013 Foris.


Another example of a modern PC display not labeled "HDR" is the Asus ROG Strix XG35VQ (2017 FreeSync LDR Gaming Display). See TFT Central Review for measured data. Has roughly the same medium dynamic range as the Samsung display, and better black uniformity.


Another example of a modern PC display labeled for "high-end HDR" is the Dell UP2718Q (2017). See TFT Central Review for measured data. This is only a 10-stop panel, so the same dynamic range as a typical poor quality PC panel.


What Does The "HDR" Label Mean For PC Displays?
The display OEMs have created a problem for themselves. They have created a dynamic range standard which is physically impossible to build LCD hardware for. "HDR" label requires 20000:1 contrast ratio, and LCD panels can do at most 5000:1. So they trade good dynamic uniformity for local-dimming. So the "HDR" label literally translates into more visual artifacts.

But it is actually a lot worse than this. Due to pressure on keeping low pricing, supporting local-dimming comes at a trade off. It appears that the increased cost of local dimming hardware takes away from the ability to use a quality panel. Notice the Dell panel has the most complex 384-zone local dimming and is pared with the worst LCD panel in the lineup. The Samsung panel is doing the best an OEM can do and still make the "marketing spec", as it is optimized to drop the cost of the local dimming to the minimum required to hit the spec by using edge lit zones, bug still ends up with a medium quality LCD panel. Unfortunately in being edge lit, the panel suffers from static uniformity problems in the darks. The non-edge lit LDR Asus display with similar dynamic range has better quality. The best dynamic range comes from the 2013 Eizo display which invested in a great PC panel. So unfortunately in practice the "HDR" label is actually translating into lower dynamic range and/or more visual error for PC displays.


Recommendations
For the Display Industry - Please make yourself a "marketing label" that is based on pixel accuracy and real panel contrast.

For Consumers - Read objective reviews based on measured data like those on TFT Central to find yourself a good display. Often the "best" displays are not the newest displays. Prefer something with high-frame rate, low display latency, low visible ghosting, something with strobed backlight support, and something with good measured ANSI contrast (near 5000:1). Also for gaming, a 1080p display on a non-CPU bound game typically approaches 4x the frame rate of 4K, so I recommend sticking to 1080p, or 1440p as a compromise for better text resolution.