The Sony Cyber-shot DSC-RX100 is an enthusiast compact camera based around a 20MP 1" CMOS sensor. It features a Zeiss-branded 28-100mm equivalent F1.8-4.9 stabilized lens featuring Zeiss T* coatings to minimize internal reflection. The rest of its specification is pretty impressive too - a 1.2 million dot 3.0" LCD (VGA resolution but using Sony's WhiteMagic technology to offer greater brightness or improved battery life), and 1080p60 video capture or 1080i with the ability to shoot a 17MP stills without interrupting movie recording. The camera can even boast a respectable 330 shots from a charge, according to CIPA tests.

Despite the availability of comparatively small, large-sensor mirrorless cameras (at increasingly low prices), the enthusiasts' compact boom has continued. Most of the big names in the industry now offer models to appeal to people comfortable with a a DSLR but wanting something easier to carry around. The RX100, Sony's first venture into this market since 2004 (with the DSC-V3) is something rather more serious.

Key Features:

  • 1"-type Exmor CMOS sensor (13.2 x 8.8mm, 3:2 aspect ratio)
  • 20.2 million effective pixels
  • 28-100mm (equiv), f/1.8-4.9 Carl Zeiss Vario-Sonnar T* lens
  • Steady-Shot image stabilization
  • ISO 125-6400 (ISO 80 and 100 expansion, up to 25,600 using multi-frame noise-reduction)
  • Face Recognition and Face Registration (up to 8 faces)
  • Rear control dial and customizable front control ring
  • 10fps continuous shooting in 'Speed Priority' mode
  • 3" 1.2M-dot 'WhiteMagic' LCD screen
  • 13 Picture Effects (27 with variations)
  • Memory Recall feature can store up to three groups of custom settings
  • 1080p60 video, (AVCHD) with MP4 option (50p in PAL regions)
  • Built-in stereo microphones
  • 330-shot battery life (CIPA)

A small camera with a big sensor

A 1"-type sensor is twice as large as the sensor in the Fujifilm X10 and 2.7 times larger than most of the rest of the class. The only comparable camera to offer a sensor larger is the Canon G1 X, which offers impressive image quality but with the payoff being bulkier styling and the larger dimensions demanded by its near-DSLR-sized sensor. Sony says the 'R' in the camera's name is intended to evoke its original high-grade fixed-lens camera, the DSC-R1, though the only similarities between the two are the ability to capture Raw image data and the ambition of their designs.

In general you can divide the enthusiasts' compact sector by body style, with the Canon S100 exemplifying the conventional compact style and the G12 representing the more bulky, dial-encrusted choices with tunnel-style optical viewfinder. Sony has chosen to go down the compact route and opted for a lens that slows considerably as you zoom in, rather than the bright zooms offered by the Olympus XZ-1, Panasonic LX7 and Fujifilm X10. This is the same balance Canon has chosen with its popular S100, but of course that doesn't have a sensor anywhere near as large as the RX100's.

Despite the large sensor, the RX100 is still pocketable. It's not the smallest compact camera on the market, but it'll fit in breast pocket of a jacket, making it a genuine carry-around second camera for DSLR owners. In principle, at least, the RX100 shouldn't present the same image-quality compromise that switching across to one of the existing compact cameras would.

Shooting for the enthusiasts

The RX100's user interface makes very clear that Sony has concentrated on making a camera that enthusiasts will be happy with. The difference between this and the beginner-focused interfaces on the Nikon 1 models (and the Sony NEX cameras when they were first launched) couldn't be more stark. The RX100 doesn't go overboard with manual controls but the now commonplace lens-encircling control dial is key to its usability. Add to this a customizable function menu - allowing you to specify which settings you want quick access to, and in which order - and you have a very controllable compact. The way Sony has done this is an extension of the options added to NEX cameras but is also reminiscent of the Ricoh control interface (still probably our favorite on a high-end compact).

And these differences from the entry-level mirrorless cameras are telling. Clearly Sony believes there is a photographically-savvy audience that wants a second camera without having to battle against a simplistic user interface or invest in a second lens system. It's pretty clear it also hopes that some existing compact owners will want something small and high quality, but will recognise themselves as part of the majority that buys interchangeable lens cameras but never takes the lens off. The RX100's $650/£550/€650 price tag may well work against this, though.

Isn't that a bit expensive?

To put this price in perspective, you have to really understand the sensor size and what it means for the camera's capabilities.

The sensor in the RX100 is the same 1" format that Nikon uses in its 1-System. It is considerably smaller than those used in most interchangeable lens cameras but it significantly larger than those used in most enthusiast compacts.

A large sensor is one of the most significant factors in terms of providing good image quality. The larger area simply means that, compared to a smaller sensor camera, it will be exposed to more light during any exposure with the same settings (ISO, shutter speed and F-number). And more light means a better signal-to-noise ratio.

To do this, the table below shows it against its peers, showing the area of the sensor, the size of the camera and the effective aperture of the camera. This last figure gives an idea of how much control over depth-of-field the camera will offer, by relating the aperture ranges back to the 135 film standard.

  Price (MSRP) Sensor area, mm2
Focal length range Focal length range (equiv.) Aperture range Aperture range (equiv.)* Dimensions, mm(bounding box**)
Sony DSC-RX100 $649 116
10-37mm 28-100mm F1.8-4.9 F4.9-13.4 101x58x36
Canon G1 X $799 262
15-60mm 28-112mm F2.8-5.8 F5.2-10.7 117x78x65
Olympus XZ-1 $499 41***
6.0-24mm 28-112mm F1.8-2.5 F8.5-11.8 111x65x42
Fuji X10 $599 58
7.1-28mm 28-112mm F2.0-2.8 F7.9-11 117x70x57
Canon S100 $429 42
5.2-26mm 24-120mm F2.0-5.9 F9.3-27.4 99x60x27
Nikon1 J1 $649 116
10-30mm 27-82mm F3.5-5.6 F9.5-15.3 106x61x72
Olympus E-PM1 $499 225
14-42mm 28-84mm F3.5-5.6 F7-11.2 110x68x84
Nikon D3200 $699 358
18- 55mm 27-83mm F3.5-5.6 F5.4-8.7 125x96x149

* Effective aperture, in 135 film terms - this gives an idea of the depth of field control offered by the lenses when the sensor size is taken into account.
** The sum of each camera's longest dimensions (the volume of the smallest box that could contain the camera, with the lens retracted)
*** Figure takes into account that the XZ-1 uses a crop from a 1/1.63" sensor.

Size and design compared...

Olympus XZ-1 and Canon PowerShot S100

Compared to the conventional compact-style enthusiast cameras, the RX100 fits in pretty well, despite having a sensor two-and-two-thirds times larger.
From the top it is clear that the RX100 is a good deal less bulky than the Olympus XZ-1 and not too much thicker than the Canon PowerShot S100, easily fitting inside a shirt pocket. Impressive given that it features a much larger sensor than either of these cameras.

Fujifilm X10 and Canon PowerShot G1 X

The RX100's 1"-type sensor is a good deal larger than that used in the Fujifilm X10 (left) but smaller than the near-APS-C sensor that Canon uses in the PowerShot G1 X. Despite falling in the middle of this trio in terms of sensor size, though, the RX100 is comfortably the smallest of the three.
As you can see from the top view, the Sony has achieved such a small body in part by omitting both a hotshoe and optical viewfinder. The RX100's fixed LCD screen and lack of a hand grip has also kept keep the body nice and slim.