The rear camera uses the Sony IMX398 16MP sensor that has the onboard Dual Phase Detection Autofocus for speedy snaps. Rear uses F1.7 aperture and the back is uses a single tone LED which is being color corrected towards pink tone. Check the video out.
In auto mode, the app exposure the scene well you can use the slide to adjust finely, but most of the time I use touch shutter instead since the exposure is accurate. For manual mode (Oppo calls it Expert mode),you can control everything except for shutter speed is either auto or slow shutter from 1s to 16s, your best bet to brighten or darken the scene after you point the focus is to adjust via exposure comp. Not a big issues since the phone is design to be simple and encourage the person to snap fast. Not very often one would change shutter like 1/125, 1/200 or 1,2500 that takes time. The autofocus speed in well lit area is fast, tiny bit slower in low light but doesn’t struggle or focus hunt (see the video for the action).
At the time of producing this review content, R9s Plus is release. The differences between the Oppo R9s Plus and Oppo R9s, is the Plus has OIS, 6GB RAM, 4000mAh battery and 6 inch screen.