Is HDR TV really a gimmick? Measured screen tells you the difference

At the end of the Spring Festival holiday, we wrote an article about 4K and HDR. We talked briefly about the 4K and HDR technologies of TV sets. Then there was a small partner asking questions in the background and I hope to further talk about HDR.
Is HDR a girl? How's the effect? This article will answer everyone's questions from technical standards and practical experience.

Too long not to read version

First of all, HDR is not a gimmick. It is a standard specification that requires both hardware and software technologies. To experience true HDR effects, you need HDR sources, devices that require HDR playback (video players, computers, etc.), and a high-end television with a wide color gamut, high peak brightness, and a 10-bit panel.

4K HDR TV to find out?

In addition, the effect of HDR depends on the display quality of the HDR source and TV, so the effect of different HDR sources on the same TV may be very different. In the following sections, there will be measured images.

Therefore, most HDRs currently advertised by manufacturers in low-end and mid-range TVs are gimmicks. Specifications such as technical parameters do not meet the requirements and they are not eligible to be called HDR TVs.

What is HDR?

In fact, HDR is still a very broad concept, and for display terminals such as TVs, HDR we are talking about should be high dynamic range video.

HDR video is not based solely on software, algorithms, or filters. This is where many buddies are prone to mistakes. To achieve HDR video requires a complete system of support, as long as there is a certain link can not meet the requirements can not achieve HDR.

Compared with SDR (standard dynamic range) video, HDR video has two major improvements. One is that the color gamut is wider, and the reduction of the color is better and more real. The second is that the contrast is higher and the darker black light is closer to the reality.

Dolby Vision HDR Effect Demonstration

In order to achieve these two points, equipment supporting the HDR standard needs to meet the BT.2020 color gamut, 10 bit depth, and specific brightness range requirements (LCD: peak brightness 1000 nit, black bit range less than 0.05 nit, OLED: peak brightness 540 nit, black level The range is 0.0005 nit, but as more display terminals support HDR, their peak brightness requirements vary according to different HDR standards and device usage scenarios.

Industry's demand for 4K HDR Blu-ray movies can be seen as the performance of HDR technology in film and television

At present, mainstream TVs generally only support the BT.709 color gamut, 8 bit depth, and the peak brightness is lower than 350 nit. How large is the gap? The 8-bit depth image has 256 levels per color channel, and 10 bits as many as 1024 levels.

The dotted line is the BT.709 color gamut range, and the solid line is the BT.2020 color gamut range.

In simple terms, the transition from black to white, 8bit images have only 256 color subdivisions, and 10bit images have 1024, so the color of the latter will be much richer, and a lot more detailed, it looks more natural and comfortable.

In summary, in order to experience true HDR effects, all hardware, including video players (or computers), display terminals, and the source (or game) viewed must support HDR. This is indispensable.

Those HDR tricky

Having looked at the technical standards of HDR, I believe we all know that HDR is not a simple gimmick but a real technical improvement. However, at present, domestic TV manufacturers are constantly putting HDR on their lips. They do not support HDR on hardware, or even add a contrast-enhancing mode to â€œimpersonateâ€ HDR functions. This is indeed a trick for this technology.

The classification of Jingdong HDR TVs was opened. The first result was a 55-inch TV selling RMB 3,999. HDR was also mentioned in the publicity.

However, when we look closely, we only support the input and decoding of HDR signals. This is totally different from supporting HDR video output.

After reading the parameters, 100% BT.709 color gamut, 8-bit panel, and peak brightness of less than 400 nit are completely incompatible with the HDR technology standard. A similar situation has also emerged with the opening of other brands of televisions on the page.

However, according to HDR's hardware specifications, what can be achieved is generally the high-end and flagship models of each, and its price is definitely higher than that of mainstream TVs.

Therefore, sometimes people complain that HDR is just a gimmick. First, they do not understand that HDR is a set of hardware and software technologies, and not just the standard of the terminal. Secondly, the problem of manufacturers catching hot targets and false targets has also caused HDR to be misunderstood by some consumers.

What is the effect of HDR?

Although we mentioned above that HDR's technology is advanced and expensive, it is a pity that the effect of HDR is not only limited to hardware but also limited to resources.

With respect to movie resources that people are most concerned about, there have been many films that have released 4K Ultra HD Blu-ray discs and support HDR 10, Dolby Vision, HDR 10+, and SL-HDR2 four HDR technology standards. In general, you only need to have a 4K Ultra HD Blu-ray disc, a player that supports its playback and an HDR-enabled TV to enjoy the new experience of 4K and HDR.

4K Ultra HD Blu-ray Disc

Of course, some 4K Ultra HD Blu-ray discs are currently cracked and users can download and watch them. However, the front said that there are certain gaps in the HDR effect between different films. We don't have such high-end HDR TVs. We use real shots of foreign media and we talk about it. The following figure shows 4K Ultra HD Blu-ray movies and FHD Blu-ray movie comparison, you can generally feel the difference between HDR and HDR:

PS: The following test results from LinusTechTips