A professional camera is also called a single lens reflex camera, and a full camera is called a single lens reflex camera. The unique design of the reflectors and prisms of these cameras allows the photographer to view the image through the lens directly from the viewfinder. When light passes through the lens of the camera to the reflector, it refracts to the focus screen above and forms an image. Through the eyepiece and pentaprism, the photographer can see the scene outside the picture window. When the shutter button is pressed, the mirror springs up and the shutter curtain in front opens simultaneously. The light through the lens (image) is projected onto the sensitive component (film in traditional cameras, CCD or CMOS in digital cameras) to sensitized it