ISO is the unit used to measure and adjust the camera sensor’s sensitivity to light. With film, the ISO setting (or film ‘speed’) is part of the film’s physical and chemical properties and can’t be changed. With digital cameras it’s possible to ‘turn up the volume’ on the sensor to make it more sensitivity to […]
This is random ‘speckling’ in an image caused by variations in the light levels captured by the photosites on the sensor. Noise is worse with the smaller photosites on small sensors and at higher ISO settings generally. You can get ‘chroma’ (coloured) noise and ‘luminance’ noise (general ‘grittiness’) the same colour as the background.
Noise is the digital equivalent of grain in film. It’s random electrical signals captured by the photosites on the camera sensor, and usually this background noise level is so low compared to the brightness of the captured picture itself that you just don’t notice it. But if you start increasing the camera’s ISO setting, the […]