An invisible line, known as the 180 DEGREE LINE or AXIS OF ACTION, runs through the space of the scene. The camera can shoot from any position within one side of that line, but it may never cross it. This convention ensures that the shot will have consistent spatial relations and screen directions.
Well the artist David Hockney believed that Johannes Vermer and other used these devices such as the camera obscura to help them achieve their perceptive in achievement
