The new Sony RX100 IV offers incredibly compelling autofocus. An exciting feature is eye AF, now available in continuous focus on the RX100 IV (and RX10 II). We have a feeling that what enabled continuous eye AF is the faster readout of the image sensor over previous models. Not only does this bring high frame rate and 4K video to these little cameras, but it also gives the focus algorithms more temporal data to work with. And looking at the speed which eyes are tracked, it certainly seems the camera is speedily taking advantage of this extra data. Of course the proof is in the proverbial pudding: the camera has to actually focus on the eye in addition to tracking it. And here the RX100 IV does not disappoint: every single shot is in focus on the eye, with the lens set wide open to F1.8, as you can see from the magnified views. And in case you missed it: 'magnify' in playback now magnifies the AF point used at capture, rather than simply magnifying the center of the frame. No more scrolling over to the point of interest in playback to check focus; you now have one-click (albeit somewhat laggy) magnification of what was focused on. This extends to all of the newly announced cameras: the a7R II, RX100 IV, and RX10 II.