[telgareith]

It's not a separate sensor- 30fps on an iPhone was more than enough.

Turns out, when you have a known luminance, white balance, and frame-rate... the DSP to grab heart rate from a finger is trivial.

[ssl-3]

Cameras can do it, yes.

But on the Galaxy S7 that I think is being alluded to here, it was definitely a separate sensor -- a MAX86902, IIRC.