Use Auto ISO in Manual mode

Your Canon camera’s Auto ISO function can be a real life-saver. Using this, you can freely adjust your exposure settings and the camera will automatically raise the ISO sensitivity at a preset shutter speed, so you don’t need to worry about camera shake when shooting handheld. It can also be used in Manual exposure mode, allowing you to set your preferred combination of aperture and shutter speed, with the Auto ISO function ensuring you get a consistent exposure in changing light.