Is the length of the camera's black box the image distance of the camera?

The distance from the object to the lens is: the object distance; The distance from the photosensitive film or CDD at the back of the lens to the lens is: image distance. Optical lenses used in modern cameras and camcorders have variable focal lengths. When the object distance changes, a clear image can still be obtained by changing the distance (image distance) from the lens to CCD or film.