The feature which everyone talked about on this phone is its front facing elevating camera. Vivo made a bold move of implementing this design decision and using it for first time, it sure felt as a novelty. At front, you get an 8 MP sensor with an f/2.0 aperture capable of recording videos at 1080p. Quality of selfies has been okay in my testing as this won't give you those stunning selfie shots that you can see from some phones, but novelty alone of it coming up from inside Vivo NEX S is sure to encourage you to boot up front camera more often.
I could watch that camera move in and out of its enclosure so many times, as it's a very fun feature indeed. It also avoids absurd solution of a bottom-edge camera, as found on Xiaomi Mi Mix 2S, for example.
At back, Vivo NEX S's comes with a 12 and 5 MP dual camera setup, which is increasingly typical for phones. Lower-resolution sensor's information can be used for depth data, which means it can produce blurred background effects (bokeh) for its Portrait mode, which has become a fan favorite all over the world after Apple's popularization of this mode. On Vivo NEX S, functionality of Portrait mode is rather similar to top-end Huawei P20 Pro. Vivo also offers an f/0.95 maximum software-based aperture, which is selected and adjusted by an on-screen slider. Automatic facial recognition ensures focus in right place, while background and foreground blurs away to dramatic effect. It's got just as many bugs with adapt edge detection as any other manufacturer's implementation of this feature, as none have got it right just yet, but it's what people want and it's fun to have on board.
There are camera AI features here like on Huawei range of products and some other devices, meaning camera will optimize its settings to take what it believes to be the best shot when you're shooting particular objects. Vivo has packed in loads of other features here too including a beauty mode, panoramas and artificial intelligence filters that will work in a similar way to Snapchat. In Vivo NEX S, functionality of Face Beauty mode is a little different to other manufacturers, but there are some similarities to Huawei P20 Pro.
As for main sensor, its 12MP is brought directly from Sony, meaning a larger-than-average pixel size for better light-gathering properties. Autofocus is good, too, while artificial intelligence handles automatic scene recognition (out of 17 available modes) for best possible picture each and every time, similar to, say, Huawei Honor 10. Phone also shoots videos up to 4K at 30 fps, however, a slow-motion mode isn't found as it can be seen on some other flagship devices, like Samsung Galaxy S9,
Overall, it's a good camera, but it's not the best you'll find. Results lack detail in certain areas, while other areas are over-sharpened which can lead to a halo effect around subject edges. Camera app could also be a bit more user friendly and quicker to offer adjustment between modes. Low-light images do resolve image noise, however, for relatively clean shots in dark at night. AI also isn't clever enough to detect movement and up shutter speed, which can pose issues for night-time shots and blur. There is a manual mode, though, which goes some way to help counter. In the end, it's still a good camera experience, and one, majority of smartphones users will appreciate.