[Brightcolours]

There can be a number of reasons for PDAF still being usually faster to focus.Including

 

1. Its been around since 1985 and so has the benefit of a longer development time in both hardware and software suppoort.

2. PDAF is simpler in terms of computer processing power,it gets to rough focus and  then ( somewhat ) refines focus. CDAF is a continuous focus system off the sensor - more accurate but each seperate focus attempt will add time to the process and all these focus attempts requires more computing power which is also of course more battery intenive.

 

So CDAF to be fast requires each focus adjustment to be performed at a faster rate which requires more powerful and more precise focus motors. It has the advantage of being more accurate and eliminates the front / back focus problems with lenses but is still a work in progress.

The A6000 uses PD AF (on image sensor PD AF).

 

Only downside to on sensor PD AF is the noise in low light.