The earliest cameras were simply light-tight boxes with a very small hole in one side of the box. By uncovering the pinhole for a brief period of time, light from an object could pass through the hole, exposing a photographic plate (film) on the inside of the box. Later versions of this type of camera replaced the hole with a lens. For a pinhole camera, the image appears upside down on the photographic plate in relation to the object.
(a) Draw a ray diagram to explain how a pinhole camera is able to form a clear image without the use of a lens.
(b) If the distance between the photographic plate and the pinhole is 30 cm, what are the size of the image for an object 10 m away and 2.0 m tall?