# ISO What is ISO mean in digital photography? In digital photography, ISO refers to the sensitivity of the camera's image sensor to light. ISO is represented by a number, with lower numbers indicating lower sensitivity to light and higher numbers indicating higher sensitivity. When shooting in low-light conditions, increasing the ISO setting can help to brighten the image, allowing you to use faster shutter speeds and/or smaller [[Aperture|apertures]] to achieve the desired exposure. However, higher ISO settings can also introduce digital noise or grain into the image, which can degrade image quality and reduce sharpness. Conversely, when shooting in bright light, lower ISO settings can be used to maintain image quality and reduce noise. However, in order to achieve a correct exposure, you may need to use a slower [[shutter speed]] and/or larger aperture, which can result in a shallower depth of field or motion blur. In general, it's best to use the lowest ISO setting possible to achieve the desired exposure, while also keeping in mind the trade-offs between ISO, aperture, and shutter speed. Higher-end cameras tend to have better noise reduction algorithms, which can allow you to shoot at higher ISO settings without as much noise. Additionally, some post-processing software can also help to reduce noise in your images.