https://www.cnet.com/news/galaxy-s10-shows-that-triple-rear-camera-phones-are-taking-over/ > It was just last year when I noticed that phone-makers were adding cameras to phones the way companies added blades to shaving razors, and at this point you may be wondering why this is happening in the first place. > There are several benefits to having three cameras on the back. The primary reason is the ability to switch between different focal lengths quickly. It is similar to a three-lens turret on an old Bolex camera that allowed you to change lenses simply by rotating the turret.