Windows Modules Installer Worker Taking Up Cpu

The reason you might want a large aperture opening (again, represented by a smaller number) would be for a portrait where you want to blur the background so that all the focus will be on the person. A large aperture opening (again, represented by a smaller number) will give you a shorter depth of field and thus a heavy focus on the subject and a blurred background. This also means that the amount of light being let in will be high, so to counteract your image being overexposed, you would either quicken the shutter speed or lower the ISO (sensor sensitivity).