Most if not all smartphones have a fixed aperture. A lower F-stop allows more light to enter through the lens. This is advantageous in low light but during the

Most if not all smartphones have a fixed aperture. A lower F-stop allows more light to enter through the lens. This is advantageous in low light but during the day it may cause pictures to wash out. Because ISO can only go so high before minor hand movement seriously blurs a photo, it is better to have a larger aperture, again for low-light conditions. So a single adjustable lens over a single sensor can allow for a variety of ideal combinations depending on the conditions.