A few years ago, the term HDR was associated with high-end, high-end TVs, and today the feature is found in mid-range products. Monitors are no exception, and more and more manufacturers are incorporating HDR technology into their products.
The essence of HDR
Having a monitor with a high-quality, high-resolution matrix, excellent contrast and color reproduction is not a guarantee that games and programs can take advantage of these benefits.
In fact, apart from special applications, ordinary programs cannot use the extended gamut of colors that the display has. Unless the hardware somehow emulates the limited color space.
This is where HDR includes its metadata to ensure correct color reproduction. HDR TVs or monitors recognize special signals and render exactly the color reproduction that the content developer has laid down in their software.
What are the HDR formats
There are many different HDR formats from the expensive and demanding Dolby Vision to the versatile and most popular HDR10. And also specialized ones like Advanced HDR from Technicolor or HLG from BBC and YouTube.
Dolby Vision
Expensive and demanding on the hardware HDR format. The display must provide a peak brightness of at least 10,000 cd / m2 and a color depth of 12 bits. A license fee is required to enable Dolby Vision technology. The format offers a dynamic implementation of metadata that adjusts brightness from scene to scene. As a result, the picture is more attractive.
HDR10
This format is less demanding in all respects with respect to Dolby Vision. The peak display brightness should be 4000 cd / m2, and the color depth is guaranteed at 10 bits. And the main advantage of this technology is the absence of mandatory license restrictions on the use of the format. Because of this, content creators and display manufacturers are opting for free and open source HDR10.
What UltraHD Premium stands for
A special organization UltraHD Alliance was created to regulate the development and implementation of relevant technologies. According to the approved regulations, the minimum technical requirements for displays for viewing HDR content must be no worse than the following:
- 4K Ultra HD 3840 x 2160 resolution;
- Support for 10-bit color, covering at least 90% of the DCI-P3 color space (125% sRGB, 117% Adobe RGB);
- HDMI 2.0;
- for LCD displays. Peak brightness not less than 1000 nits, black level not less than 0.05 nits, contrast ratio 20,000: 1;
- for OLED displays. Peak brightness at least 540 nits, black level at least 0,0005 nits, contrast ratio 1,080,000: 1;
Most monitors and TVs meet the above requirements only to a limited extent. Accordingly, they partially provide support for the HDR format. To be sure that the product you are purchasing supports true HDR, you must ensure that you have the dedicated UltraHD Premium logo. This mark means that the display is approved by the UltraHD Alliance.
Separating HDR from VESA
In December 2017, VESA (Video Electronics Standards Association) defined new HDR standards. An additional five separate groups were identified. Three for LED displays - DisplayHDR 400, DisplayHDR 500, DisplayHDR 600. And two for OLED displays - DisplayHDR 400 True black, DisplayHDR 500 True black.
Focusing on this marking, you can accurately assume what quality the monitor was purchased. It should be understood that devices labeled "HDR" can simply receive an HDR10 signal and emulate the image quality using software. This solution is called "pseudo-HDR" or "fake HDR".
According to VESA, the DisplayHDR 400 specification is the least demanding in terms of hardware. It has a high peak brightness and wide color gamut. Compared to basic HDR10, this specification is characterized by a better picture quality. But a lot depends on the manufacturer of the product and the quality of the components.
What is monitor dimming
To noticeably improve image quality, LED-backlit monitors use display dimming. This allows you to achieve significant image contrast. In simpler devices, darkening a portion of the image will darken the entire screen. And with the introduction of new HDR standards, local dimming was implemented in hardware.
Local dimming is mandatory since the DisplayHDR 500 specification. Unlike simple monitors, more advanced models dim only part of the image.
There are two types of local dimming implemented in hardware in displays. Edge-to-edge LED backlighting and full-array local dimming (FALD) backlighting.
Display edge lighting has fewer dimming areas, but can still provide good image contrast. This technology is cheaper to implement than FALD.
FALD local dimming technology currently provides the best contrast and image quality. Separate LED lighting elements are mounted in the screen matrix. This allows you to control the backlighting and dimming in certain places on the display. FALD monitors are expensive, and not all monitor manufacturers offer FALD devices.
HDR in PC games
There are many PC and console games developed with HDR support. Moreover, manufacturers of the gaming industry are actively finalizing previously released products for the HDR format with updates and patches.
However, there are still many technical difficulties in implementing HDR. Since the bulk of software products are not ready to work with advanced formats. For example, Windows 10 forcibly tries to adapt software for HDR. And in some cases, visualization of products that are not intended for this becomes terrible to perceive. Then you need to manually change the settings before each launch.
Conclusion
HDR is a controversial thing. There are nuances that affect the final image quality. There are monitors that offer terrible HDR quality but have other strengths. On the contrary, monitors adapted for HDR may have weak key characteristics, but due to the original HDR markings they are in a higher price segment.
In any case, when buying it is worth reading, looking at the reviews. Collect as much information as possible and make the right choice.
