I understand that Phase Detection delivers faster autofocus vs Contrast Detection. How does this play out between an X20 and OM-D? Any users here who have used both the cameras? Can you please share your thoughts?
But to say phase Detection AF is genrelly faster is wrong. The fastness also depends on the lens motor, and the CPU and sotware in the camera and mostlike a lot mor tiny details.
The main different between phase detection (PD) and contrast Af (CD) ist, that the PD AF "knows" where the focus should be by comparison of two points and then drives the lens to the right position, while the CD AF drives the lens throu the whole range of possible distances and searches the point where the strongest contrast (and there for sharpest) is. To know this, it hast to drive over that point->and that is the real weakness, because on video it dosnt look good if the picture gets over the sharpest point.
The Om-D (and some othe Cameras) with the right lens is faster then most (non pro) DSLR cameras-if the X20 is as fast as that? i hope so
Theoretically, these new hybrid, PDAF/CDAF, systems might be faster (and more precise) - they use the PD information to narrow the range to which the CDAF is applied. But, as Tim pointed out, the actual AF speed and accuracy depends on how everything is implemented in software and (lens) hardware. For example, one of the things that makes the OM-D so fast is the very fast AF motor in the newer Olympus lenses (e.g., m.zuiko 12mm and m.zuiko 17mm f1.8).