The camera can now hit 24fps for continuous shooting, but the real improvement here is the modern autofocus system -- it's fast and accurate.
Like the A6500 that was announced at the same time, the update to the Sony RX100 IV gets new internals for faster shooting, but the difference between the RX100 IV and RX100 V is far more noticeable -- because the performance bar set by the RX100 IV isn't very high. The updated autofocus system is a huge jump over the RX100 IV, though the specsmanship-level 24fps continuous shooting means Sony now needs more than ever to improve the speed of writing files to the card.
The RX100 V will be available this month for $1,000 -- I'd watch for price drops on previous models, because the RX100 IV is currently the same price. It's slated to ship in Europe in November for €1,200, which directly converts to about £885. While it's on the Sony Australia site, I can't find price or availability details; the US price directly converts to about AU$1,320.
The RX100M5 has the same body, internals and features as its predecessor: same 20.1-megapixel resolution and image processor, same popup viewfinder, same extensive set of 4K video capabilities and high frame rate (HFR) shooting modes.
But the new version of the 1-inch sensor includes phase-detection autofocus pixels, Sony's Fast Hybrid autofocus system, in addition to the old, slow 25-area contrast autofocus. That makes a huge improvement in action shooting -- locking focus and tracking subjects -- as we've seen from other Sony cameras that have moved to the system.
Under the circumstances under which I got to try it, with fast vertical motion but no fast horizontal movement, it performed extremely well, grabbing focus and tracking quite fast and accurately. Still, we were in a low-light environment (ISO 1250 and up for the shutter speed necessary) so it's impossible to tell how sharp the photos really are; the high ISO sensitivity shots look relatively sharp, but not at full size. As far as I can tell, they also look about the same as the RX100 IV.
It's supplemented by new processing hardware and a larger memory buffer, which Sony claims allows it to achieve 24 frames per second for continuous shooting, with autoexposure and autofocus, for 150 shots. That's pretty impressive. And possibly overkill for most people.
However, the bandwidth between the buffer and the SD card doesn't seemed to have changed; in other words, it's really slow to write bursts and video to the card. So after that 24fps burst, you can still start another, but for any other operation you see nothing but the message saying it's writing to the card. The buffer let me shoot 141 best-quality JPEGs at 10fps, but it was minutes before I could change a setting. And shooting so many photos burns through the already middling battery life. The battery lasted a lot longer than rated -- at least 2,100 shots, for me, because I didn't use any flash -- but that was basically an hour and a half. It's really easy to do that during continuous shooting, and even easier if you're at the 24fps rate.
The new silicon also enables Sony to double the maximum length of a high-frame-rate recording to about 7 seconds, for 1080/240p video. There are also some tweaks to settings for existing features. The HFR processing speed hasn't changed, though, and it still takes a l-o-o-o-o-o-ng time for it to process and write to the card. The implementation is still annoying as well -- you switch into HFR mode, then have to put it in standby before you can start recording. You can't zoom once you're in HFR either, so if you've forgotten to set up the shot beforehand, you have to jump out.
Along with the camera, Sony announced an underwater housing for the entire RX100 line rated for 40 meters (130 feet). It's expected to ship in the US in November for $350. (Directly converted, about £200 or AU$330.)
Improved focusing? Count me in. Same goes for the longer HFR recording. The autofocus system really keeps up with the continuous shooting, at least for the limited types of action I was able to try it with. Given that it's extremely similar to its predecessor -- including the slow writing-to-card -- the autofocus alone is a reason to pick the RX100 V over the RX100 IV. But my final verdict awaits further testing.