What action does the ISO setting on a camera control?

The ISO setting on a camera specifically controls the light sensitivity of the image sensor. When you increase the ISO setting, you make the sensor more sensitive to light, allowing for better performance in low-light conditions. Conversely, a lower ISO setting means less sensitivity to light, which is ideal for shooting in bright conditions to maintain image quality and reduce noise (graininess).

This feature is crucial for photographers as it helps them achieve the desired exposure of an image without necessarily relying on longer exposure times or wider apertures, which can lead to motion blur or reduced depth of field. Adjusting ISO is a key component of the exposure triangle, which also includes aperture and shutter speed, allowing for creative control over the final image.

Understanding how to effectively use ISO settings can greatly enhance a photographer's ability to capture quality images in varying lighting environments.