Operation and controls
The RX100 III gains the latest version of Sony's user interface, which is being harmonized across its Alpha and Cyber-shot cameras. This means it gets the fully customizable Fn menu we first saw on the a7 and a7R. This allows you to put six or twelve functions of your choice onto a one or two-deck Fn menu. Being able to arrange the functions in the order of your choice means you can cluster together those functions you tend to adjust at the same time (AF mode and AF point selection mode, or HDR and JPEG/Raw, for instance).
|The RX100 III gains the customizable Fn. menu introduced in the a7 and a7R.|
The rest of the interface will be pretty familiar to existing RX100 or recent Sony users. You can choose which types of display you want to be available, then cycle through them using the DISP button. The available displays can be set separately for the EVF and the rear screen, so purists could easily set the viewfinder to show just the image being composed, with the basic shooting data along the bottom of the finder, if they wanted. There's even the DSLR-like option of having the rear screen showing all the camera's settings on Sony's interactive 'Quick Navi' display.
|You can set the RX100 III up so that the viewfinder and rear screen show different displays.
For instance, you can set the viewfinder just to show the image you're composing...
|...while the rear panel displays the Quick Navi settings display, as soon as you take your eye away from the camera.
The Quick Navi panel is interactive: press the Fn button in this display mode and you can navigate around most of the settings shown on the display, to change them.
The RX100 III has the same smooth-turning control ring as the preceding models. By default its function is connected to the shooting mode you're in (so it controls aperture in Aperture Priority mode and program shift in Program mode, for example). Alternatively you can customize its function - this one function is then applied regardless of exposure mode (It's increasingly common for rivals to allow you to define dial function per-exposure-mode).
Sadly, the same level of control doesn't extend to the rear dial, instead in most modes it simply duplicates the standard function of the control ring (manual exposure mode being the exception). On the plus side, this means that customizing the control ring doesn't deny you access to the setting it would usually control - it's also useful in Manual Focus mode, where its function is supplanted by focusing duties. However, it also means that you can't decide which ring you want to control which setting: if you want to have full-time access to exposure comp, then it has to be the front dial that controls this.
As well as being able to re-purpose the front control ring, the RX100 III also allows you to assign functions to the 'C' button, the 'left' and 'right' buttons on the four-way controller, and the button at the center of that control. There are 42 settings that can be applied to any of these buttons.
The Center button also has a default setting of 'Standard' - we'd recommend leaving it at this setting if you evermanually position the autofocus point, when you shoot, since pressing it accesses AF point selection when in 'Flexible Spot' AF mode (it's at least one extra button press, otherwise).
*The 'hold' functions (that require the button to be held down), cannot be applied to the 'left' and 'right' buttons, presumably because it would be hard to hold the camera and keep these buttons depressed.
The RX100 III's Auto ISO system is essentially the same as that found on previous models: you can set the upper and lower ISO limits that it will use, but there's no option for specifying the threshold at which it changes. As such, the camera will increase the ISO based on the focal length you're shooting at, with the camera using a minimum shutter speed of 1/30th of a seconds at wide-angle and 1/80th at full zoom.
However, one significant change is that you can now use Auto ISO when in Manual mode - effectively creating a Pentax-esque 'Shutter and Aperture Priority' mode. This is a fully functioning exposure mode in its own right, since it's possible to apply exposure compensation. To do this it's necessary to customize the front dial or one of the customizable buttons to control exposure comp - but it is possible.