Which expert can explain to the system what HDR, HLG and HDR10 mean in photography?

1. High-Dynamic Range (HDR), compared to ordinary images, can provide more dynamic range and image details. According to different exposure times, LDR (Low- Dynamic Range, low dynamic range image), and use the LDR image corresponding to the best detail at each exposure time to synthesize the final HDR image. It can better reflect the visual effects in the real environment.

2. HLG: The full name of HLG is Hybrid Log Gamma. It is a high dynamic range HDR standard jointly developed by the British BBC and Japan's NHK TV station. HLG does not require metadata and is backward compatible with SDR. Compared with HDR10, its images can be presented more vividly even on existing SDR display devices.

3. HDR 10: HDR10. On August 27, 2015, the hdr10 media file released by the American Consumer Electronics Association, commonly known as hdr10, uses the recommended 2020 color space, Perceptual Quantizer (PQ), and 10-bit Bit depth. hdr10 is supported by a variety of companies.

Extended information

HDR’s best partner: OLED TV

1. The picture quality improvement brought by HDR technology is intuitive and perceptible, even for ordinary Viewers can also distinguish it with the naked eye, so this year many manufacturers have equipped their TV products with HDR technology.

2. But even so, not all TV products can be a "good match" for HDR technology. After all, the application of HDR technology is not a single link, but is related to the entire ecosystem of screen display.

3. Two conditions are required to present perfect HDR. The first is high contrast, and the second is excellent color expression. OLED TV is different from traditional liquid crystal display technology. It abandons the backlight and realizes organic self-illumination of each pixel, which means that each pixel can be turned on or off independently. It has unlimited contrast, wide range of Color gamut, wide viewing angle and other advantages. Therefore, HDR can be fully displayed on OLED TVs.

4. First of all, the most important thing for HDR is contrast. The lowest brightness that an LCD TV can display is 0.1nits, the brightest is between 500 and 1000nits, and the contrast ratio is only 5000:1.

5. If the brightness is doubled to 10,000 nits, it can only reach 10,000 to 1. The lowest brightness that LG OLED can display is 0.0005nits (the lowest brightness that can be detected by current brightness measurement instruments), the highest is 500nits, about 20 levels, the contrast ratio is 1 million to 1, plus the lowest brightness (0.0005nit ) is almost zero. So it's equivalent to having a contrast ratio that's close to infinite.