What happens when you increase the ISO setting on your camera?

Increasing the ISO setting on your camera enhances the sensor's sensitivity to light. This means that at a higher ISO, the camera can capture images in lower light conditions without requiring a longer exposure time. A higher ISO is particularly beneficial in situations where there is little available light, allowing you to achieve a properly exposed image without resorting to a flash or increasing the aperture width (which could result in a shallow depth of field).

It's important to keep in mind that while increasing ISO improves sensitivity, it can also introduce more noise, which manifests as graininess in the image, especially in very high ISO settings. This explains why other choices do not fit the correct answer: decreasing the amount of light or reducing noise under low light are not outcomes of increasing ISO, and making images softer does not directly relate to ISO changes.