What do you mean by promotion and demotion?

Change the normal shooting speed. Above 24 frames per second, it will be upgraded, and below 24 frames per second, it will be downgraded.

Upgrading is a technical means in film photography. The shooting standard of cinematography is 24 frames per second, so as to shoot continuous pictures at normal speed. But in order to realize some simple techniques, such as slow-motion effect, it is necessary to change the normal shooting speed.

If you improve the shooting speed, it is an upgrade, and the screening effect is slow motion. If you slow down the shooting speed (below 24 frames per second), it is degraded, and the screening effect is fast action.

influencing factor

1. shutter speed and optical input

Pay attention to the shutter speed when shooting the upgrade screen. Generally speaking, under the premise of not affecting the image quality, the shutter speed is twice the shooting frame rate, so that there can be motion blur relatively suitable for the naked eye.

For example, under the premise of not affecting the normal exposure, the shutter of 1/50s is used for 24 frames, and the shutter of 1/250s is needed for 120 frames. However, when the shutter speed is set to 1/250s, the shot picture may be a little dark, indicating that shooting upgrade requires more light input than ordinary lens.

Second, pay attention to the jitter of the picture.

Slow motion shooting will reduce the picture jitter to some extent, but it may not be able to recover the picture jitter when shooting some moving scenes or moving mirror combinations. In order to ensure the overall texture of the video, a stabilizer is needed when shooting and upgrading.

Upgrade can not completely replace the role of stabilizer, especially in the use of mobile upgrade screen and mobile mirror transition. It is very limited to reduce the picture jitter only by upgrading in post-editing.