Underwater Photography Glossary

Often compared to "grain" in film, there is a level of noise in each digital image you capture, which appears as tiny speckles of color. Noise is caused by simple physics, created by the photon nature of light and the thermal energy of heat. Sometimes it is less noticable than others. Each pixel in a camera sensor contains light sensitive photodiodes which convert the incoming light (photons) into electrical signals which are then processed into the final image. Even without incoming light, the electrical activity and heat of the sensor itself will generate some image noise. Higher ISO sensitivities and long exposures create more noise.