Professional vocabulary about photography

1, focal length: the distance from the center of the lens to the clear image formed on the film plane.

2. Aperture: A device used to control the amount of light passing through the lens. When the aperture is increased by one step, the amount of light entering the camera is doubled, and the aperture is decreased by one step, and the amount of light is halved. The aperture size is expressed by f value.

3. Shutter: A device used to control the exposure time. Shutters can generally be divided into mirror shutters and point curtain shutters.

4. Depth of field: When the object is gathered clearly, it is clear from a certain distance in front of the object to a certain distance in the back, and the distance before and after the focus is clear is called depth of field.

5. Exposure: The process that light reaches the surface of the film and makes the film sensitive.

6. Relative aperture: the ratio of the effective aperture of the lens to the focal length. The larger the relative aperture, the faster the lens speed.