What is the function and function of photography? What are the factors that determine the depth of field and its practical value? What are the factors that affect exposure?

Photography is a process of recording visible objects and scenes with lenses and photosensitive materials under static conditions. Its function depends on the parameters of lens and film sensitivity in applied photography, which determine different images: dynamic, fuzzy background that highlights the subject, static of fast moving objects and so on.

The factor that determines the depth of field is the combination of aperture and speed. If the aperture is larger and the depth of field is smaller, the speed must be adjusted higher. Conversely, the smaller the aperture, the greater the depth of field and the slower the speed. Its main value lies in: large depth of field can be applied to large groups of photos or panoramic landscape photos, which can be seen from near to far. If the small depth of field is suitable for taking some close-ups and snapshots, it can blur the messy background and highlight its main effect.

The factors that affect exposure are the application of film sensitivity, aperture and speed, and of course mainly depend on the light source on the spot, so flash is also the main light source that affects exposure.