In photography, the amount of light your camera picks up can make or break your photo. Your camera’s digital sensor has an adjustable sensitivity to light – this is what’s known as ISO, and Fujifilm’s Glossary Series is here to shed some light on how it works. In the days of film, ISO represented the film speed, which had a direct correlation to light sensitivity. In modern digital cameras, ISO is controlled by the photographer. The rule of thumb is the lower the ISO setting, the lower the digital sensor’s sensitivity to light, and vice versa. Experimenting with and adjusting your ISO can help you get the perfect shot in virtually any lighting conditions.