However, unlike shutter speed and aperture, changing the ISO doesn’t actually capture more or less light.
ISO is the third camera setting that changes how bright and dark your photo is. However, unlike shutter speed and aperture, changing the ISO doesn’t actually capture more or less light. Instead, it’s a lot more similar to changing a photo’s brightness in post-processing software like Photoshop. (More on how that works in our detailed ISO article here.)