The periscope lens

How submarine tech could mean better iPhone photos

- CARRIE MARSHALL

KEY FACT

To get a longer-range zoom, you need to increase focal length — the distance between the lens and camera sensor. In a normal camera, you do that by making the lens move outwards — for example, by having a telescopic lens. Telescopic cameras have been tried in smartphones but they weren’t too successful.

ACCORDING TO MULTIPLE well-connected Apple leakers, the iPhone could be getting a new kind of camera in 2022; one that sees further than any existing iPhone camera without having to sacrifice any image quality.

That’s because Apple is experimenting with periscope lenses. It wouldn’t be the first to do so, either. Samsung’s Galaxy S20 and S21 Ultra both have periscopes, and other Android firms are following suit with their own high-end products. So what is a periscope lens, and why would you want it in your phone? Let’s — ahem — look into it.

WHY PERISCOPES CAN HELP YOU SEE SO MUCH FURTHER

Periscope lenses enable you to get much more powerful optical zoom without requiring an enormous lens sticking out of the back of your phone. To understand why that’s important, we need to understand how optical zooms work, and why digital zooms aren’t as good.

With optical zooms, you get the same level of detail, no matter how much you zoom in or out; with digital zoom, the software tries to guess what detail a zoom lens would see. It’s clever, but no substitute for the real thing.