How a Camera Works?

A camera is likened to a dark room into which light enters only through a small hole in the window shade. On the opposite wall of the wall of the room, this light produces a dim inverted image of the object or scene outside the window. The lens of a camera admits light in the same manner. The light that passes through the lens forms an image on the film. A device called a shutter opens to let light enter the camera. It opens when a shutter release is pressed to take a picture.

A camera has a viewfinder which a photographer looks through to aim at the subject. The relationship of the distances between the lens, the subject and the film determines the sharpness of the image. The distance between the film and lens can be adjusted by a focusing machine before the shutter release is press to take a picture.