Few compact cameras have garnered as much attention as the Sony Cyber-shot RX100 and RX100 II. Sony had managed to squeeze a much bigger sensor into some cameras only a little larger than the Canon S-series enthusiast compacts. And, in common with the S-series and Fujifilm's XQ1 they struck a pragmatic balance between zoom range and lens speed. They could boast an F1.8 lens at the wide end of things, but were down to a less impressive F4.9 at the full extent of their zooms.

The RX100 III strikes a balance much more like that of Panasonic's LX series - a more consistently fast lens and wider angle starting point, with the trade-off of less reach at the telephoto end. On the RX100 III, Sony is using a new 24-70mm equivalent F1.8-2.8 lens, which is both faster and wider than what was on its predecessors, though at the expense of telephoto power. When you combine its fast lens and larger-than-average sensor size, the RX100 III promises stronger low light performance and shallower depth-of-field at the telephoto end than most other enthusiast compacts.

While the lens is no doubt impressive, the feature that will probably get the most attention is the RX100 III's pop-up electronic viewfinder which, as far as we know, has never been done before. Not only is it 'cool,' but it gives you the flexibility of having an EVF available at all times, without adding significant bulk to the camera. The inclusion of a viewfinder puts the RX100 III in very select company, even amongst enthusiast compacts.

Key Features:

  • 20.1 megapixel 1"-type Exmor R BSI-CMOS sensor
  • 24-70mm equiv. F1.8-2.8 Carl Zeiss Vario-Sonnar T* lens
  • Pop-up SVGA OLED electronic viewfinder with 1.44M dots
  • 3-inch tilting WhiteMagic LCD with 1.23M dots
  • 1080/60p video with full sensor readout and 50Mbps XAVC S support
  • Clean HDMI output
  • Zebra pattern and focus peaking
  • Customizable front lens ring
  • 3-stop neutral density filter
  • Wi-Fi with NFC and downloadable apps
  • 320 shots per charge (CIPA standard)

As mentioned above, the lens on the RX100 III is considerably faster than its predecessors, though the telephoto end of the lens now stops at 70mm, instead of 100mm of the RX100 Mark I and II. What's impressive, though, is how Sony was able to create a much faster lens with only a small increase in camera size.

To allow those bright maximum apertures (along with the lower levels of diffraction and shallower depth-of-field they bring) over a broader range of circumstances, Sony has managed to fit in a neutral density filter. This can be engaged in bright light, when the 1/2000 sec maximum shutter speed isn't sufficiently fast. It also allows the use of wide apertures when using the long exposures that movie shooting requires.

There's a lot more to the RX100 III than just the lens and EVF, though - especially when it comes to video. The RX100 II was certainly no slouch in that department, and the Mark III offers some major improvement. The first is full sensor readout, which allows for higher resolution video than your typical compact (or interchangeable lens) camera, a feature we first saw on the Cyber-shot DSC-RX10. The RX100 III also supports the XAVC S codec, allowing for 1080/60p recording at 50Mbps, which is a considerable improvement over the 24 and 28Mbps rates on the Mark II. The RX100 III can also output 'clean' HDMI video over its HDMI port.

Something we didn't particularly care for on the previous two RX100's was the shooting experience. The user interface, cluttered controls, and, in particular, the 'clickless' wheel around the lens that gave no tactile feedback just took the 'fun' out of using the RX100 Mark I and II. While the EVF should make outdoor photography more pleasant and there have been minor tweaks to the UI, there hasn't been as much change as we were hoping for.

RX100 Series Comparison

Seeing how there are now three members of the RX100 family, we thought it would be a good idea to sum it all up in a table:

RX100 II
Bionz X
Lens focal range
Lens max aperture
LCD (degrees of tilt)
3" tilting (180/45)
3" tilting (90/40)
3" fixed
Hot shoe
Max video bit rate
50MBps (XAVC S)
28Mbps (AVCHD)
Yes, with NFC
ND filter
Battery life (CIPA)
320 shots
350 shots
330 shots
102 x 58 x 41mm
102 x 58 x 38mm
102 x 58 x 36mm

Add to this the Bionz X processor, and all the features it brings, and the RX100 III represents a much larger step forward than we saw between the original RX100 and the II.

The Bionz X processor brings three main changes to the camera's JPEG processing: more subtle sharpening ('Detail Reproduction Technology'), that is aperture aware ('Diffraction Compensation') and context sensitive noise reduction. On top of this, the latest processor brings the two-line, 12-item customizable function menus we saw in the a7 cameras, plus 'Zebra' over-exposure warnings and a more sophisticated 'lock-on' autofocus system. Finally, the latest version of Sony's user interface includes the option to install PlayMemories Camera Apps onto the camera itself, adding functions such as time-lapse shooting. A variety of apps are already available, some of which are free, others of which must be paid for separately.

That new lens

We've already told you that the RX100 III's lens is much more ambitious than those of its predecessors, offering a much-improved maximum aperture range and a wider starting point (if you don't mind the drop in telephoto reach). Sony is immensely proud of one of the technologies it has developed: the combination of two aspherical lens elements. This has been key to allowing such a wide and bright lens to be built into such a compact design. The lens can focus as close as 5cm at wide-angle and 30cm at the long end of the zoom.

Sony's optical designers have managed something that the company says has never been done before: bonding two aspherical elements together.

What does this mean in the real world, though? Have a look at the equivalent aperture comparison chart below:

Just like 'equivalent focal length,' equivalent apertures allow you to compare lens behavior side-by-side across cameras with different sensor sizes, by taking sensor size into account. The equivalent aperture figure gives a clear idea of how two lenses compare in terms of depth-of-field. It also gives an idea of low-light performance, since it also describes how much light is available across the sensor's area. However, differences in sensor performance mean this can only be used as a guide, rather than an absolute measure.

Between 24 and 28mm, only the G1 X Mark II has a larger equivalent aperture. The RX100 II comes into play at 28mm, and it's actually effectively 'faster' than both the G1 X II and RX100 III at first. After that, the G1 X II stays in the lead across the chart, with the RX100 III keeping up until it hits the 70mm telephoto end of its lens. At 70mm, the RX100 III is more than a full stop faster than its predecessors.

So when will you see this benefit? First, since the fast lens allows more light to hit the sensor, it improves image quality, particularly in low light. Also, the lower the equivalent aperture, the shallower the depth-of-field. While the RX100 III won't perform as well as the G1 X II in this regard (particularly since the Canon is at its best at longer focal lengths, which the Sony doesn't offer), it's still excellent by compact camera standards.

The 24-70mm lens range won't be to everyone's tastes, of course, and the graph above makes clear that 70mm equivalent means giving up quite a lot of reach, compared to its rivals (it never gets to the 85-135mm equivalent range considered ideal for portraiture, for instance). That said, 24-70mm has been a popular standard zoom range on full frame cameras for decades, so it's not exactly unprecedented, as a 'walkaround' focal length range.

Sony RX100 III overview video