What is high dynamic video?

In photography, dynamic range refers to the brightness range of the subject, that is, the brightness span of the subject from the darkest point to the brightest point.

Photographers often use differences to quantify the dynamic range. Every time the exposure is doubled or halved, it is called increasing or decreasing 1EV. The exposure meter can measure the brightness of this area as nEV.

The dynamic range can be expressed by the difference of EV between the highest brightness area and the lowest brightness area in the scene. For example, in order to take soft portrait photos, you can illuminate the scene or use props to control its dynamic range within 3EV, which means that after the lighting is completed, the luminosity values of the brightest and darkest areas in the picture will not exceed 3EV.