Numbers on the camera lens (understanding the importance of lens parameters)

The number on the camera lens is an important parameter that photographers must know. These numbers represent the key information such as the focal length, aperture and focusing mode of the lens, which directly affects the imaging effect of the photo. Knowing the meaning and function of these numbers when purchasing lenses or shooting can help us to choose and use lenses better and take better photos.

First, the focal length

Focal length refers to the distance from the optical axis of the lens to the imaging plane, usually expressed in millimeters (mm). The longer the focal length, the narrower the angle of view and the shallower the depth of field of the lens, which is suitable for shooting distant objects, such as landscapes and buildings. The shorter the focal length, the wider the viewing angle and the deeper the depth of field, which is suitable for shooting close objects, such as people and flowers. Common focal lengths are 18-55mm, 50mm, 70-200mm and so on.

Second, the aperture

Aperture refers to the maximum luminous flux of the lens, usually expressed by F number. The smaller the f-number, the larger the aperture, the greater the light input and the shallower the depth of field, which is suitable for shooting dark scenes or emphasizing subjects, such as portraits and flowers. The larger the F number, the smaller the aperture, the smaller the light input and the deeper the depth of field. It is suitable for shooting bright scenes or scenes that need overall clarity, such as landscapes and buildings. Common apertures are F 1.8, F2.8, F4, etc.

Third, the focus mode

Focusing mode refers to the focusing mode of the lens, including manual focusing and automatic focusing. Manual focusing requires manual adjustment of lens focal length, which is suitable for shooting static scenes or scenes requiring fine focusing, such as macro photography; Auto focus is to automatically adjust the focal length through the camera's focusing system, which is suitable for shooting dynamic scenes or scenes that need quick focus, such as sports and wild animals.

Fourth, the operation steps

Choose the right lens. According to the shooting scene and demand, choose the lens with appropriate focal length and aperture.

2. Adjust the focus mode. According to the shooting requirements, choose manual or automatic focusing mode and make corresponding adjustments.

3. Adjust the aperture. According to the shooting scene and demand, choose the appropriate aperture and adjust the aperture value of the camera.

4. Adjust the focal length. According to the shooting requirements, adjust the focal length of the lens and choose the appropriate angle of view and depth of field.