What is respiratory effects's shot?

Respiratory effects refers to the slight change of focal length when the lens changes focal length.

The structure of the lens itself is very complicated, especially the lens group. Different lenses have different functions. When you want to change the focus in the picture when shooting, the focusing lens group in the lens will start to move and focus.

Because some lens groups begin to move, sometimes this displacement will affect the positions of other lenses and lens groups, even if it is only a slight change, it will also cause a slight zoom effect. This change is called "respiratory effects" of the lens. Reflected on the screen, when the focus is switched, the image in the screen will change size, and this phenomenon will happen in the focus of Jiao Wai.

Extended data

In fact, in theory, all injections have respiratory effects. Just because of the different design of lens structure, the breathing produced is also strong and weak. Excellent lens, in the design process of lens group, will pay special attention to this problem, weigh the lens volume, weight, imaging quality and other factors, and try to reduce the respiratory effects of the image.

Respiratory effects is generally imperceptible to still photography. Every shot is a single static image, and there are not many continuous pictures, but it is different for video shooting.

The video itself is a continuous picture. Many times, the video will be watched on a larger screen, which will make the breathing effect easier to be noticed. For video, it will distract the audience more or less because of respiratory effects's image.

References:

Nikon China-The lens that can "breathe", is it really good?