What is ISO? ISO is your digital camera's sensitivity to the image sensor. It determines how much light is let into the lens, for example my camera has a low setting of 100 and can go all the way up to 6400. The lower the number the lower amount of light is let in, if your camera is set to the highest setting it will be super bright creating an overexposed image. When taking pictures inside where it is dark a higher ISO will help you take a clear image without flash. When taking outside pictures where it is bright, a lower ISO will work. In class I took a picture of the light fixture in every ISO setting that my camera allowed. My first couple images turned super dark, but once I got up to ISO 0f 1600 my image was clear. I learned a lot from this activity because I have never really messed with my settings for inside shooting which caused a lot of issues for me before.