The E-M5 ships with a brand new M.Zuiko Digital ED 12-50mm f/3.5-6.3 EZ kit lens (24-100mm in 35mm equivalent). It offers a further range than the previous kits 14-42mm (28-84mm in 35mm equivalent) which have shipped with the PEN cameras. As a weather-sealed lens, it complements the E-M5 well; taken together the E-M5 becomes a camera you shouldn't be worried to carry into the (light) elements (it's weather-sealed, not weather-proof).
But like the Panasonic X 14-42mm lens which ships with the Panasonic GX1, we're not sold on the electronic zoom on the new lens. Our main grippe is that there are no focal length markings on the lens, unlike on a traditional lens. So there's no way to see, at a glance, just how far along you are on the zoom range before raising the camera to your eye and adjusting accordingly.
Still, while we dislike this disadvantage of the lens, it's because we're accustomed to using our lenses this way. If you don't have this habit, then it's likely you won't mind – there are certainly people who like the Panasonic X electronic zoom lens as much as we dislike it.
The Olympus lens handles better than the Panasonic X 14-42mm lens, in our opinion; because you can switch between manual and electronic zoom simply by sliding the zoom ring backwards or forwards. In electronic zoom mode the zoom ring only twists slightly left and right, the longer you hold in each direction the further the lens will zoom. This benefits videographers who'd prefer to have a smoother zoom then twirling the zoom ring will allow. In manual zoom the ring goes all the way round both ways.
The mode ring presents its own challenges because it's easy to slide it accidentally when holding or storing the camera, forcing you to look at the mode indicator to check which zoom mode you're in. Olympus actually solved this problem, but only for the third Macro mode on the lens; you have to press and hold the Macro button on the lens to be able to slide the zoom ring all the way to Macro. In our opinion the lens would have benefitted from a lock button for all three modes.
While the E-M5 feels good in the hands, it feels perfect with the optional HLD-6 power battery holder. While it adds size and heft to the camera, it also adds comfort, functionality and of course, battery life – with the additional battery the E-M5's lifespan is nearly doubled to 650 shots (as rated by CIPA). The HLD-6 battery holder doesn't come with any additional batteries. PEN owners, unfortunately, won't be able to use their existing batteries as the E-M5 uses a new battery type.
The battery holder comes with additional two additional shutter releases. The one in front sits on top of a prominent and comfortable grip; the one on the side is orientated for comfortable portrait shooting. The holder even comes with two additional control dials for use in portrait orientation, as well as two additional customizable Function buttons. Having the battery holder affixed also solves the strap problem somewhat; by providing a more prominent front grip your fingers can more comfortably push down the strap and reach beyond for the shutter without having the strap intertwine between them.
This battery holder is a first for a mirrorless system camera. While it makes the E-M5 less portable, it also transforms the camera into something resembling a high-end DSLR. It's an odd feeling to use a small Micro Four Thirds like a large DSLR camera, but it also feels really good for those used to the feel of a DSLR. While the HLD-6 is an optional accessory, it adds so much to the camera that it feels like it the battery holder should just come with it.