What are the basic knowledge of photography?

Exposure in photography simply refers to the process that light enters the camera and leaves an image on the photosensitive element inside the camera. The size of the aperture and the speed of the shutter determine the exposure, while ISO determines the exposure speed of the camera. According to the intensity of light entering the camera, photographic exposure is usually divided into normal exposure, underexposure and overexposure.

Second, measurement.

In order to get accurate exposure, it is necessary to measure light when shooting. Photometry in photography is realized by the camera's built-in photometry system and external exposure meter. Because the external exposure meter is rarely used, the metering mentioned now is mainly aimed at the built-in metering system of the camera.

Simply put, the camera measures the light of the scene through the photometric system, and gets a correct exposure value, and then sets the appropriate aperture and shutter according to this exposure value. This process of measuring exposure value is called photometry. Taking Canon as an example, the built-in metering system of the camera can be divided into evaluation metering, partial metering, spot metering and central metering.

Third, focus.

Focusing is one of the important links in shooting. When shooting, if the focus is not accurate, the picture will be blurred, even after the later period, it is irreparable. Camera focusing can be divided into automatic focusing and manual focusing. Usually, when we shoot with the shutter half pressed, we often hear a beep, which is a hint of successful focusing through the camera's autofocus function. Auto-focus is divided into single auto-focus, continuous auto-focus and intelligent auto-focus according to the number of focusing times during shooting.

Four, aperture, shutter, ISO

The aperture shutter ISO can be said to be the most important thing in photography. All the shooting is realized around these three changes. Because the knowledge of the three is relatively large, I won't talk about them one by one here, but only explain their respective functions, so that beginners can have a general understanding and lay the foundation for subsequent learning. The so-called aperture is a large or small round hole composed of a group of small iron sheets on the lens.