The Sony Cyber-shot DSC-RX100 III (aka RX100M3) is quite a different animal from its sibling, the Editors' Choice. With a manufacturer price of $800 (£700, AU$1,100) it costs about $150 (£110, AU$200) more, and targets enthusiasts willing to pay more for a faster lens, improved video quality, and an electronic viewfinder. And the M3 is an appealing camera for that group, albeit not without causing some aggravation along the way.
Because the camera incorporates the newer Bionz X processing engine, you get some enhanced features over the M2, including Lock-On (tracking) autofocus and adjustable autofocus area size. For video shooting, it incorporates the higher bitrate 50Mbps XAVC S codec in additon to the veteran AVCHD and MP4 codecs; a dual-video record mode that will let you shoot low-resolution video for wireless upload alongside the better-quality video; Zebra (tonal clipping indicator); and clean HDMI output. Because Sony expects it to be used for video, it also has the Intelligent Active Mode IS which compensates for shooting while walking, though it's missing a mic input.
Both its still and video image quality are excellent for its price class -- and even beyond, in some cases -- though that's not without caveats. The camera incorporates a new 24-70mm f1.8-2.8 lens, with a faster aperture than the lens on the other two RX100 models, and which uses the Zeiss T* coatings. Of course, it's all about trade-offs: you lose a bit of the zoom range in exchange. I think it's worth it, however.
Depending upon how you plan to use them, the photos can be considered acceptable through the top of its sensitivity range, ISO 12800, although you probably don't want use those shots at 100 percent. The processing and noise reduction are okay, though even at ISO 400 you can start to see some mushy edges and the not-terribly-smooth out-of-focus areas that typify small-sensor cameras. Nevertheless, in-focus areas still look good up through ISO 1600.
The tonal range is just okay, though it's still better than the Canon PowerShot G1 X Mark II. You can recover highlight details that aren't too blown out and shadow areas at lower ISO sensitivities. At about ISO 800, the range starts to compress and clip the dark areas, but that's pretty common. Colors generally render accurately, even with the default Standard Creative Style, though it does clip the highlights a little more than I'd like. It does have a Neutral setting, though, unlike the RX100M2.
The RX100M3 supports Sony's high-bitrate XAVC S codec, and the videos shot with it look better than anything I've seen from a compact camera. While they still show edge artifacts like jaggies and edge crawl, even in low light you don't get the typical crackling caused by color noise in motion. The camera supports dual record -- it simultaneously captures XAVC and MP4 -- but the MP4 is pretty low quality and pretty much just for reference or very small playback. The AVCHD looks great as well. It's too bad the camera doesn't have a mic input, though, because the sound isn't terrific.
The biggest caveat here: In order to record the XAVC video you need a 64GB SDXC Class 10+ card; the manual only obliquely specifies this (in the card capacity section, under XAVC S, it simply doesn't list anything for the other capacities). But don't buy a Sony card. It works fine in the camera, but is the slowest card for file transfers I've seen in years, taking hours to do what takes minutes with other cards.
The RX100M3 ekes out some performance improvements over the M2, turning it into one of the faster models in this class. The camera defaults to Pre-AF enabled -- Sony's term for semicontinuous autofocus -- which we turn off for testing. I personally don't like leaving it turned on; the sound of the lens constantly in motion irritates me and shortens battery life.
Given that battery life is so short when using the EVF, which I think is far more useful, that it's worth saving where you can. Also, the battery takes almost 4 hours to charge, but you can easily drain it in half that time. Carry a spare.
That said, I did spot checks of the performance with and without Pre-AF during testing, and overall there was generally no significant difference between the two.
However, I did have problems getting the camera to focus on the correct spot. I finally ended up using the smallest spot focus choice for lab ISO sensitivity photo samples; with the medium or large spots it focused in front of the subject. During the performance testing at its widest angle, though, even the smallest center spot didn't work.
Time to power up and shoot is still a bit slow at 2 seconds, but time to focus and shoot in bright light is an excellent 0.2 second and a decent-for-its-cohort 0.4 second in dim conditions. Two sequential shots runs just under 0.2 second for raw or JPEG, which is excellent. With flash enabled it increases to 2.1 seconds, a lot slower than the M2 and on the high side.
Continuous shooting with autofocus enabled actually fared better than its specifications, achieving 2.9fps for raw and 3.3fps for JPEG, with no drop in speed up for at least 30 shots.
The autofocus works well enough, though it's not stellar on objects in motion; I really wouldn't use this camera for shooting action if the results matter to you. For instance, the list of conditions under which the Lock-on AF (tracking autofocus) won't work includes: low light, overly bright light, varying levels of brightness, and objects too small or too large.