Performance

Overall Performance

As you should be able to expect for a camera at the level of the E-M5, it goes about its business rapidly enough that you never really notice it. If you try to shoot bursts of images using a relatively slow SD card you'll find yourself waiting, but otherwise, unless you start shooting bunches of Art Filter images, you'll rarely notice any delays when shooting with the E-M5. Which, in turn, means you rarely notice the camera at all.

Focus in good light is impressively fast and continues to be pretty quick until the light gets very low. In situations where you're using the camera's highest ISO settings because you have to, you'll find the focus spends a bit of time hunting, and you'll have to start thinking about the contrast level of your target. Overall though the EM-5 turns in a good performance, especially by mirrorless standards.

Continuous Shooting and Buffering

The E-M5 boasts the ability to shoot continuously at up to 9 frames per second. To achieve this you have to sacrifice autofocus (which is locked at the first frame, along with the exposure) and live view, which is replaced by a view of a previously-taken image. Even so, for the occasional burst to grab a moment's action, it's a nice feature to have, even if these restrictions limit the usefulness of the viewfinder while panning.

Timing
JPEG Large/Fine
RAW
RAW+JPEG SFine
Frame rate 9.2 fps 9.0 fps 9.0 fps
Number of frames 16 16 15
Buffer full rate 2.7 fps 2.0 fps 1.0 fps
Write complete 4.8 sec 7.5 sec 13.8 sec

All timings performed using a 64GB SanDisk Extreme Pro UHS-I SDHC card (90MB/s)

Even shooting Raws alongside the excessively large Superfine JPEGs (the largest amount of data the camera can produce for a single exposure), the E-M5 can maintain nine frames per second, at the cost of a longer wait for it to finish writing.

The E-M5 also has a reduced-speed continuous shooting mode, in which the camera maintains live view between frames and can track autofocus on a moving subject - in principle at least. Image stabilization is turned off by default, but can be enabled in the menu. The speed this mode works at can be configured in the menu; out-of-the-box it's set to 3.5 fps, but can be set to 4, 3, 2 or 1 fps if you prefer. Olympus says the camera will only achieve 4.2fps with IS Off, with IS limiting the frame rate to 3.5 fps.

The E-M5 really appreciates a fast, modern (UHS-I) card, especially if you're hoping to use its continuous shooting capability. We tried using an older SanDisk Extreme III, 30MB/s (which was once our benchmark timings card), and found we had to wait for the camera to respond after shooting a run of images. With a UHS-I card, this isn't an issue, so it's worth investing in a new card if you do want to use the E-M5's continuous shooting option.

Image stabilization

One of the E-M5's biggest changes over the existing PEN series is its '5-axis' image stabilization system. While claims of 5-stop improvement are wildly over-optimistic from our experience, it is certainly effective in-use. The system comfortably allows you to shoot at low shutter speeds (e.g. 1/15th of a second at 100mm equivalent) where all but the most considered hand-held shooting gives shaken images. Despite its ability to compensate for translational motion, the performance isn't quite so impressive at close working distances, with Macro work requiring a push of ISO to keep the shutter speeds higher.

The multi-axis IS system requires the sensor to be held in place when the camera is in use, a process that generates a slight humming noise. This is present whenever the camera is switched on, though it becomes quieter during video shooting. You're only likely to notice it in quiet situations and it's not loud enough to distract your subjects, so it's unlikely to ever have any effect on your shooting experience.

The image stabilization is pretty effective. It doesn't guarantee steady shots but does increase the likelihood of them.

This shot, with IS On was taken at a 80mm equivalent focal length, at 1/8th of a second shutter speed.

Image stabilization is disengaged in continuous shooting, by default (The slightly confusing 'Sequential Shooting + IS Off' setting in the Custom menu needs to be changed to 'Off' to turn IS on). Olympus says that the IS doesn't work as well in continuous shooting but, even at the 9fps setting, we found it offers a significant improvement in the number of sharp shots. IS is also very impressive indeed in movie mode (see our video page for more details).

For the first time in an Olympus camera, the E-M5 can be set (Using the 'Half Way Rls With IS' option in section C of the Custom menu), to engage the IS system when you half press the shutter, meaning that the preview is stabilized when you're trying to shoot with long lenses. It also means you can get a stabilized image when trying to use magnified live view for fine focus (you must also set the 'LV Close Up Mode' option in section D of the Custom menu to 'Mode 2' to prevent the half-press from cancelling the magnified view).

Autofocus speed / accuracy

Olympus claims that the E-M5 offers the fastest autofocus in the world when paired with the 12-50mm F3.5-6.3 lens (at least for for single focus acquisition), and we have little reason to doubt that. The focus is near-instant in good light and only drops off in very low light. Being based on contrast detection (that directly assesses the sharpness of the image), there's little reason for concern about accuracy - a principle borne-out by the hundreds of correctly-focused images we've taken.

However, despite Olympus' claims about improvements in continuous autofocus and subject tracking capability, we found the system too slow and unpredictable to develop much enthusiasm about. If you're careful about making sure the camera has locked onto a subject, you can expect to get a couple of sharp shots out of a burst but the results are patchy and, for the kinds of 'grab the moment' shooting you'd want it to work for, the results simply aren't reliable enough. The EM-5 is far from unusual in this respect (Continuous AF isn't a strength of contrast-detection AF), but for such an expensive model, and one for which Olympus is pushing the continuous AF capabilities, it's a disappointing result.

Tracking is a particular disappointment. If you specify an AF point, the camera will usually 'lock-on' to the correct subject but it gets very easily distracted. No matter how distinct the subject might appear (being the only red item in the frame, for instance), the camera will often decide it's much more interested in the background after a couple of frames. This, combined with the continuous AF's hunting, means you simply can't rely the system to get your shots in focus.

Unhelpfully, the camera doesn't indicate that Continuous Autofocus is not available in high-speed (9 fps) mode, and during shooting, you may never realize. With continuous tracking AF activated the focus tracking target will still move around the viewfinder as you capture your high-speed images, but the clue lies in the hundreds of out-of-focus shots that you'll end up with - the camera might behave like it's trying to track the subject, but focus is actually fixed at the first frame of the burst. To get tracking AF you have to shoot in Continuous L mode.

Battery life

The combination of an electronic viewfinder and small body mean the E-M5 isn't able to compete with large DSLRs in terms of battery endurance. The CIPA figure of 360 shots per charge is pretty standard for a mirrorless camera - the compact body and live view mean it can't come close to the 1100 offered by the Canon EOS 60D, for example, when used with the optical viewfinder. However, the 60D's battery life drops to 320 shots when used in live view mode, so all things considered the E-M5 doesn't give a terrible performance.

We've spent days shooting with the E-M5 where we've run through an 8Gb card before running out of battery, but for multi-day trips or high-intensity shooting, we'd recommend investing an a spare BLN-1 to be on the safe side (or use one in the optional battery grip).