Tuesday, 21 February 2012
ISO is used to control the camera sensor’s sensitivity to light. The ISO value is likened to the ASA value used in film. The higher the value the more sensitive it is to light.
Increasing the camera sensor’s sensitivity to light allows faster shutter speeds to be attained. This is particularly useful when shooting indoors when light levels are low.
ISO is referenced in full stops. With each ISO stop increase (higher ISO value) double the amount of light is recorded by the sensor. With each ISO stop decrease (lower ISO value) half the amount of light is recorded by the sensor.
The table above shows ISO values in full exposure stop increments.
Be careful however, the more you raise the ISO of your camera, the more noise will appear in your photos.