What is HDR?

What is HDR?

In conformity with the television standard, most movies we watch on a TV can only be played back with limited brightness. These video specifications have prevented perfectly faithful reproduction of very bright or well-lit subjects. In high-contrast scenes, bright areas may have tended to look overexposed if dark areas were emphasized, or vice versa. Unlike this Standard Dynamic Range (SDR) of brightness, High Dynamic Range (HDR) offers an expanded range of brightness. Because HDR movies retain a wider spectrum of brightness, bright or well-lit subjects look more natural and realistic. Less likely to look over- or underexposed, these movies are more nuanced and expand your creative palette.


An international standard for HDR is Recommendation ITU-R BT.2100, and when you set Picture Profile for shooting in HDR, your movies will conform to these specifications. Of the two HDR gammas (perceptual quantization (PQ) or Hybrid Log-Gamma (HLG)), Picture Profile uses HLG. As for gamut, the same specification in BT.2020 standards for 4K/8K TV is adopted in BT.2100. However, for consistency with other cameras and functions, it is described as BT.2020.

Advantages of shooting in HDR

Only a very narrow range of brightness provides suitable exposure for conventional SDR, so SDR movies may lack detail in highlights or shadows (be over- or underexposed). In contrast, a broader range of brightness provides suitable exposure for HDR movies, and the wide dynamic range makes these movies less likely to look over- or underexposed. Even scenes with suboptimal exposure are less likely to have problems, and scenes that were difficult to shoot optimally with automatic exposure (AE) will generally look fine with HDR. From another perspective, by capturing brighter or darker scenes, for example, you can control brightness as an element of your movie's mood. Knowing this will help you take full advantage of the creative potential of HDR.

Controlling exposure as you shoot usually requires you to check the video level on a waveform monitor. Without one, you can use the camera's built-in zebra function, or the zebra indicator, which shows the zebra setting level on a histogram. These are easy ways to check for overexposure in bright image areas.

To check HDR video, you will also need a display monitor compatible with that format. Fortunately, [Gamma Disp. Assist] enables convenient checking of HDR video on the camera monitor or viewfinder. This feature emulates an HDR monitor, and although it is not intended for full HDR display, it reveals the details of your movies captured with HDR.

Note

  • For optimal playback of HDR movies recorded in [HLG/1/2/3] on a Sony camera via an HDMI cable, you will need to adjust the picture quality settings of your Sony TV. In the picture quality settings on the TV, set the gamma to an option compatible with HLG, and set the color mode to an option compatible with BT.2020 or 709.