ISO sensitivity refers to the sensitivity of the image sensor on a digital camera. High ISO sensitivity allows you to take pictures in low light. However, high ISO sensitivity can also cause noise, or graininess, in the photograph.
Basics
ISO originally referred to a camera film's sensitivity to light. In digital cameras, ISO stands for ISO 12232:1998 specification, a noise ratio and brightness standard set by the International Organization for Standardization.
Default ISO
100 ISO is considered a "normal" setting. The ISO cannot be adjusted in some digital cameras, but other cameras automatically adjust the ISO setting or allow users to manually change the setting.
Altering the ISO
Increasing your ISO setting may improve pictures shot in low-light situations, especially settings that don't permit flash photography, such as concerts or churches. Higher ISO settings also enable you to shoot with a faster shutter speed, which may improve sports photography.
Tags: digital cameras
