Sony says that it uses high-density tracking autofocus borrowed from its high-end mirrorless models, a first for a CyberShot camera. The superzoom can focus at 0.03 seconds with full AF and exposure tracking and buffer up to 249 images. That's enough to shoot a 10-second, 20-megapixel 24fps video clip, by the way. Sony also offers a new electronic, anti-distortion shutter that reduces "rolling shutter," and it can fire photos completely silently in all modes, including at continuous high speeds.
Other features, including full sensor readout 4K video, and 960 fps super slow mo (at 912x308 resolution) for up to 4 seconds), remain as before. The model also keeps the superb, f/2.4-4, 24-600mm equivalent Zeiss zoom lens with optical stabilization. ISO range is limited to 100-12,800, expandable to 25,600.
Now let me break the bad news to you. The Sony RX10 IV costs a mind-blowing $1,700 (£1,800 in the UK), which is even more expensive than the $1,500 RX10 III, and we thought the pricing on that was ridiculous. As we pointed out then, for the same sum, you can get a pretty decent mirrorless camera and several cheap zoom lenses. What you're effectively spending the money on with the RX10 IV is the portability and, it has to be admitted, a pretty damned fast 600mm f/4 zoom. It arrives in the US and UK in October.