We got a NEX S unit from vivo and went on a tour of the city a perfect opportunity to shoot some camera samples. The company has not confirmed it officially, but we think that the rear camera is similar to the one on the X21.
That means a 12 MP sensor (with 1.4µm pixels), a relatively bright f/1.8 aperture and Dual Pixel AF. The secondary camera (used for bokeh) has a 5 MP sensor with f/2.4 aperture.
vivo NEX S camera samples: daylight
vivo NEX S camera samples: indoors
It has 4-axis optical image stabilization (OIS), which the X21 lacks, so it should perform better in low light. In Pro mode you can push the exposure time up to 32 seconds, but you'll need a tripod if you want to shoot that long.
vivo NEX S camera samples: low-light
Here's what the second camera on the back does - it helps with bokeh shots.
vivo NEX S camera samples: rear camera bokeh
And finally, a quick test of the panorama mode.
vivo NEX S camera samples: panorama
Then theres the selfie camera, which is interesting not so much for its sensor or lens but for how its mounted. The camera is hidden inside the body of the NEX S like a periscope but it extends automatically as soon as you open the camera app.
For completeness sake, the selfie camera has an 8 MP sensor and a lens with f/2.0 aperture. It can do bokeh shots too, despite being alone.
vivo NEX S camera samples: selfies
Both cameras benefit from AI enhancements, which adjust the camera settings based on the scene. In fact, vivo has tacked on an AI label to several camera features, including HDR, filters and beautification.