05-02-2012, 05:41 PM
Sadly, I don't really know more. My wild guess is that the vivid profile pushes the contrast, rendering AF easier ?
http://forums.dpreview.com/forums/readflat.asp?forum=1041&message=41294319
http://forums.dpreview.com/forums/readflat.asp?forum=1041&message=41294319