Using the OM-D E-M5
Until you've held one, it's hard to appreciate just how small the E-M5 is. It's little bigger than the size of an PEN E-PL3 with an additional hump for the electronic viewfinder. This means it has a fairly minimal hand grip, which may concern some users with bigger hands. There is a nicely-designed two-part grip available, which means you can add a more substantial front grip without having to add a portrait grip to keep size down. Even without it, though, we found the camera is easy to hold and use. The magnesium alloy body is reassuringly weighty and solid.
The camera's small size means all the controls are pretty small and close together. Thankfully the two top-plate control dials are a good size, and can be configured to operate pretty well exactly how you want using the Dial function setting in the Custom B menu. You can set them individually for each exposure mode, so if you want the front dial to control exposure compensation in A mode but shutter speed in S and M (for example), that's just fine.
The rear, inboard dial is placed quite close to the viewfinder, which can be a little restrictive for wearers of glasses who favour their left eye. But even for those people it's far from unworkable - in fact you can operate it with your index finger rather than your thumb (just as long as you don't use the add-on grip). This is one of the only times you're likely to be concious that some ergonomic compromises have to be made to offer so much control in such a small package.
By default the rear 4-way keys are used to reposition the AF point around the frame, which makes this an easier and more direct operation on the E-M5 compared to its most-obvious competitors, particularly when you're using the EVF. For example the Sony NEX-7 and Panasonic DMC-G3 both require you to press - and therefore locate - a button first before you can move the AF point.
In your hand
HLD-6 Power Battery Holder
If the EM-5 is too small for you, or if you like working in the vertical orientation, Olympus makes a grip, called the HLD-6. Unusually, it comes in two parts, and adds a second shutter button and front dial for landscape-format shooting. However it doesn't inactivate the analogous controls on the camera body itself, so you can choose to use whichever you find more comfortable.
However, while the grip certainly offers a better hold of the camera, we're more equivocal about its effect on the overall handling. It forces you to adopt a slightly different hand position, and we've found that this can make access to the rear and top-plate buttons (Fn1, Fn2, and in particular movie record) more awkward. As always, this sort of thing is a matter of individual preference, but you may wish to try before you buy.
Specific handling issues
Overall the E-M5 is a joy to use, and its huge level of customizability means that you can set up the controls more-or-less exactly as you see fit. So if you're uncomfortable with the default setup it's well worth persisting and trying different combinations of options - chances are you'll be able to set the camera to suit your style of shooting.
It's worth pointing out that E-M5 has no dedicated ISO control, although its reasonably-intelligent Auto ISO means you may be happy to delegate this function to the camera entirely. If not, then simply pressing the 'OK' to bring up the onscreen Super Control Panel allows you to access ISO easily enough. Alternatively you can assign ISO to the Fn2 or movie record buttons (although not, oddly, to Fn1).
Most of us found the slightly recessed and indented movie Record button was well differentiated from the raised Fn2 button, making it easy to access video with the camera to the eye. However, some of those in the dpreview office found it a little fiddly, and found themselves accidentally hitting 'Fn2' when trying to initiate movie recording. If you shoot a lot of movies and have the same problem, you can always assign movie recording to one of the more prominent buttons, including Fn2.
|This view illustrates two of the issues that you might encounter with the EM-5 from time to time: the small Fn1 button's location so close to the rear thumb rest, and the proximety of 'Rec' to the Fn2 button.
Not everyone found this problematic, but you may find yourself wanting to put your most-used functions on the buttons you find easiest to find when shooting.
Several users in the office have reported dissatisfaction with the small size of the Playback and Fn1 buttons and their recessed position above the fold-out rear screen, which can make Fn1 awkward to operate with the camera to your eye. Not everyone found this to be problematic, but the small controls do require a degree of precision. The four-way controller is also a little cramped; ironically the first weather-sealed mirrorless camera is impossible to use confidently while wearing gloves.
Auto ISO limitations
The E-M5's Auto ISO settings are usefully configurable - you can set both the minimum and maximum limits, and thankfully there's no artificial limitation on the highest ISO you can use. By default Auto ISO is available only in the PAS modes, but you can set it to be available in M too. Note however that there's no way of applying exposure compensation when using Auto ISO in M mode.
|The E-M5 allows you to set both the lowest (Default) and highest ISO you want the camera to use in Auto ISO.
Auto ISO settings are in the Custom E menu - there's also a separate option to enable Auto ISO in M mode.
In general, the camera will attempt to set a 'handholdable' shutter speed according to the '1/equivalent focal length' rule of thumb, or 1/60th sec (whichever is faster). However, this limit of 1/60th is actually defined by the 'Flash Slow Limit' setting in section F of the Custom menu, allowing you to force the camera to push the ISO up if you need to retain fast shutter speeds, or drop lower if you're using a wide-angle lens and are willing to trust the IS system (which will help eliminate camera shake but obviously won't freeze subject motion).