The Nikon V3 features sensitivity upto -3EV to + 3EV
Now -1 EV equals to 1.25 Lux and -0.5 EV equals to 1.75 LUX.....
So the Nikon V3 / 1 series camera PDAF AF system will work prefectly even in 1 or 2 Lux of light
"A camera with a 1-lux rating claims to be able to produce an image by the light of one candle that is about three feet away from the subject. Many cameras on the market today can do just that. The problem is that the resulting image may be of very poor quality."