ABSTRACT
The “controlled amount” of light mentioned in exposure’s definition is determined by factors both outside and inside the camera: on the outside is the weather, the chandelier, the studio light, or any other light in the scene, some of which is under the photographer’s control, while some is not. The letters ISO stand for International Organization for Standardization, an organization that sets a standard for sensitivity in digital cameras and film, among many other things. As of 2017, this standard is published under ISO 12232:2006. Noise, in short, is variation in an image’s color and brightness that does not actually exist in the object being photographed. In other words, noise is something that the camera “imagined.” Just as a higher ISO setting on a digital camera produces more noise, a higher speed rating for film increases the image’s graininess. This is because film’s grains work like a digital camera’s photosites: each grain is a unit of light-sensitive material.
