Xiaomi's 13 Ultra comes into focus

Variable aperture should improve one of the best phone cameras

Welcome back to Multicore for Tuesday, April 18th.

Xiaomi has just announced its highest-end phone for 2023, the Xiaomi 13 Ultra. This issue went out slightly later than usual in order to include the announcement.

The 13 Ultra's key feature is its quad camera system. The Xiaomi 13 Pro, which I reviewed back in February, was and still is my favourite phone camera to date, with its one-inch sensor and Leica-assisted colour tuning helping to produce photos that look notably different to any other phone. The 13 Ultra builds on this with an extra periscope lens and an unusual addition to the primary camera: a variable aperture.

Specifically, the main camera still has a one-inch sensor but the lens now has two aperture settings: f/1.9 and f/4. The former lets about twice as much light in as the latter and will allow for shallower depth of field. That's usually a desirable ability, but with the move to larger image sensors in phone cameras, these small fixed-aperture lenses can sometimes render less of the photo in focus than you might expect. By stopping down to f/4, you'll get greater sharpness across the frame.

Xiaomi isn't the first company to ship a phone with a variable aperture; Samsung's Galaxy S9 from 2018 could switch between f/1.5 and f/2.4. The difference in depth of field was pretty minimal, though, given the tiny sensor size. Samsung ditched the feature for the following year's Galaxy S10. With Xiaomi's one-inch sensor, the effect should be more pronounced.