The iPhone 15 Pro Max will feature a periscope lens, a feature that allows phone cameras to achieve high levels of optical zoom. Traditional optical zoom, which requires physical lens movement, is limited by the thin profile of modern smartphones, but the unique configuration of periscope lenses solves that problem.

A periscope lens is a unique lens configuration that uses a prism or mirror to redirect incoming light at a 90-degree angle. This allows the lenses to extend the length of the phone instead of being constrained by the thin profile of the device.

This configuration is called a periscope lens because the mirror or prism that redirects incoming light works via the same mechanism as a traditional periscope. However, it doesn't actually raise the camera above the phone like a traditional periscope does, since the vertically oriented lenses are all contained within the body of the phone.

Because the periscope configuration provides much more room for physical lenses, it allows for much higher levels of optical zoom than would be possible with a traditional phone camera. Optical zoom requires physical lens movement to adjust the zoom level by moving one or more lenses relative to each other, and the vertical alignment enabled by the periscope lens allows for a much greater range of motion.