Turns out the OnePlus 7 Pro's telephoto lens can't deliver 3x optical zoom

The telephoto lens on the OnePlus 7 Pro only goes up to 2.2x optical zoom.

What you need to know

• The OnePlus 7 Pro's optical zoom is closer to 2.2x and not 3x.
• The telephoto lens is cropping 13MP photos down to 8MP to get to 3x zoom.
• Unlike the OnePlus 5, this isn't digital zoom — you're basically losing out on focal length.

One of the marquee features on the OnePlus 7 Pro is the camera array at the back, where a 48MP primary camera is joined by an 8MP telephoto lens and a 16MP wide-angle lens. OnePlus advertises the telephoto lens with 3x optical zoom, but it turns out that's not actually the case. As discovered by /u/ImKuya on Reddit, the telephoto lens doesn't actually deliver 3x optical zoom, but closer to 2.2x.

The OnePlus 7 Pro uses the telephoto lens for portrait shots, but the field of view is different when using portrait mode and 3x zoom. Turns out the sensor itself is a 13MP Samsung S5K3M5, and the telephoto lens is cropping 13MP photos down to 8MP to hit 3x zoom. As noted by our friends over at Android Police, OnePlus is effectively cropping the edges to hit the zoom target, and in doing so you lose out on the field of view.

OnePlus advertises the telephoto lens with a 78mm focal length, and that's in line with what you'd expect from a 3x optical zoom lens. But because the sensor is cropping down to 8MP, the effective focal length is 57mm, or a zoom factor of 2.2x.

This isn't the first time OnePlus was caught misleading when it comes to the camera on its devices. The manufacturer had to walk back claims of 2x optical zoom on the OnePlus 5 after it was found that the phone was only capable of 1.6x zoom. OnePlus clarified after the fact that the remaining 0.4x was achieved via digital zoom:

Optical zoom is at 1.6x, the remaining 0.4x is realized through SmartCapture multiframe technology.

— Carl Pei (@getpeid) June 21, 2017

The company isn't using digital zoom in this scenario, but it isn't delivering full 3x optical zoom either. Guess it's time to update the marketing materials.