What does "out of focus" mean?

In photography, "out of focus" means being unable to focus.

Out-of-focus means that the focus is out of alignment, that is, the place that should be clear is blurred, or it looks very clear, and it is blurred after a certain magnification.

Focusing refers to adjusting the focal length when using a camera, which is called Focus in English. Generally, digital cameras have various focusing modes, namely, auto-focusing, manual focusing and multiple focusing modes. Focusing is also called aiming light, focusing. The process of changing the distance and the position of the distance through the camera focusing mechanism to make the image of the object clear is focusing.

The key points are as follows:

(1) autofocus: traditional cameras use a method similar to line-of-sight measurement to achieve autofocus. The camera emits an infrared ray (or other rays), determines the distance of the photographed object according to the reflection of the photographed object, and then adjusts the lens combination according to the measurement result to realize automatic focusing.

(2) Manual focusing: Manual focusing is a focusing method that adjusts the camera lens by manually turning the focusing ring, so as to make the photos taken clear. This method largely depends on the human eye's judgment of the image on the focusing screen, the photographer's proficiency and even the photographer's vision.

(3) Multifocal: Many digital cameras have multifocal function or area focusing function. When the focus center is not set in the center of the picture, multi-point focus or multiple focus can be used.

(4) Holographic autofocus: Holographic AF is a unique function of Sony digital camera and a brand-new autofocus optical system. It adopts advanced laser holography technology and uses laser spot to detect the edge of the object, so it can take accurate focused photos even in dark environment, and the effective shooting distance is 4.5 meters.

(5) Mobile phone focusing mode: laser focusing. Simply put, the distance between the target and the test instrument is calculated by recording the time difference between the infrared laser emitted by the equipment, reflected by the target surface and finally received by the range finder.