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 […]
Many cameras offer extended (expanded) ISO settings beyond the standard range. These can help you out in an emergency but they’re not designed for everyday use because the image quality is significantly reduced. Some cameras also offer expanded low settings such as ISO 50.