The E-M1 is the second model in Olympus's OM-D series and extends the range further into semi-pro/enthusiast territory. There are two main distinctions that set the E-M1 apart from its little brother (the E-M5) - a more sophisticated autofocus system and a 'buttons for everything' design approach. As such the two models will coexist, with the E-M1 sitting at the very top of Olympus's lineup.

The biggest technological step forward on the E-M1 is the addition of on-sensor phase detection elements, giving the camera two distinct focus modes. The phase-detection system is used when lenses from the original Four Thirds system, which were designed for use that way, are attached. With native, Micro Four Thirds lenses, the camera will mainly stick with the contrast detection system that has proved so fast and accurate on the E-M5. Only if you use tracking AF will the camera utilize phase-detection information with a Micro Four Thirds lens.

The E-M1 also gains the excellent 2.3M-dot electronic viewfinder panel we first saw as the VF-4 accessory for the PEN E-P5. Not only is the resolution very impressive, but the viewfinder optics give a viewfinder with magnification of up to 1.48x (depending on display mode), which puts it only a fraction behind the 0.76x viewfinder in Canon's 1D X and ahead of Nikon's pro-grade D4 DSLRs.

There's also a more advanced 'TruePic VII' processor in the E-M1 that conducts a variety of lens corrections, when creating JPEGs, leading the company to proclaim the best image quality offered by one of its cameras. Not only can the E-M1 remove the colour fringing caused by lateral chromatic aberration, Olympus says that it also tunes its sharpening to take into account the lens's sharpness, and to combat any softening due to diffraction (particularly at very small apertures).

The biggest difference between the E-M1 and the E-M5, though, is the degree of direct control on offer. We really liked the E-M5's twin-dial control system, but the E-M1 goes beyond that by providing button-and-dial combinations for quickly changing almost every imaginable setting on the camera. It's the kind of approach you don't usually get until the very top of manufacturers' lineups - it means you have to get used to where every function is, but can shoot fluidly once you have.

The E-M1 inherits the '2x2' dial approach Olympus previously used on the E-P5 - flicking a switch on the camera changes the dials from controlling shutter speed, aperture or exposure compensation to changing ISO and white balance. However, all this direct control doesn't come at the expense of the potentially slower but easier to find touch-screen interface - the E-M1 has this too. Overall the camera can be operated pretty much however you fancy.

Olympus OM-D E-M1 specification highlights:

  • 16MP MOS Four Thirds format sensor with no low-pass filter
  • On-sensor phase detection elements
  • Twin control dials (front and rear) with '2x2' dual-mode option
  • '5-axis' image stabilization with automatic panning detection ('S-IS Auto')
  • ISO 'LOW' (100 equiv) - ISO 25,600
  • Up to 10fps continuous shooting (6.5 fps shooting with continuous AF)
  • 1.04M-dot 3" LCD touchscreen display - tilts 80° upwards and 50° downwards
  • Electronic viewfinder: 2.36M-dot LCD, 0.74x magnification (equiv.), eye sensor
  • Built-in Wi-Fi for remote shooting and image transfer to smartphone or tablet
  • Dust, splash and freeze-proof (to -10 °C)

Gained over the E-M5

  • True Pic VII processor, with lens corrections
  • 1/8000 sec top shutter speed, 1/320 sec flash sync
  • Built-in microphone socket (rather than optional accessory adapter)
  • Flash X-sync socket
  • Built-in Wi-Fi
  • Focus 'peaking' display
  • In-camera HDR blending (two modes), previewed in viewfinder

Four Thirds is dead. Long live Four Thirds.

As well as representing the highest-end Micro Four Thirds camera yet, the E-M1's role is also about offering continued support for users of the original Four Thirds SLR system. Olympus created some very nice Four Thirds lenses, but the company struggled to make enough impact in the SLR market to justify the cost of continuing development for both systems in parallel.

The company claims to have studied what the E-M1 and a hypothetical 'E-7' SLR could offer, and concluded that, while image quality, durability and speed would have been the same, the OM-D design allowed both a substantial size advantage and a much greater viewfinder magnification than would be possible with an optical finder. As such the E-M1 should be considered the successor to the E-5.

We'll look at the performance of the camera with Four Thirds lenses in a little more depth later in this article. But in principle, the on-sensor phase detection autofocus system should be much more effective than contrast detection when it comes to controlling Four Thirds lenses, all of which were primarily designed to be driven by phase detection-based systems.