1 1 What are the three important parameters of the photographic objective? What properties do they determine respectively?

Three important parameters of photographic objective are (focal length), (field angle) and (relative aperture). Where (relative aperture) affects the image plane.

Illuminance and resolution.

For a photographic system, the longer the focal length, the smaller the depth of field. The larger the diameter of the entrance pupil, the greater the depth of field.

(small); The farther the shooting distance, the greater the depth of field.