ISO is a feature that allows you to take control of your image by measuring the camera's sensitivity to light.
Slide up on the joystick navigation to launch the camera. Tap on the settings icon on the left side of the shutter button and slide left on the advance control toolbar to see more options. Tap on the ISO icon.
Tap on Auto to activate the slider. Using the slider, you can adjust the ISO.
Using the slider, you can increase or decrease your ISO. Based on where you leave the marker, the number equivalent will show for the exposure. Tapping AUTO will bring you back to automatic ISO.