The 2.0x crop factor of Micro Four Thirds cameras really plays into your hands for extending telephoto reach, but it makes seriously wide viewing angles a major challenge. This lens from Olympus's 'Pro' line rises to that challenge, being equivalent to a seriously wide 14-28mm zoom on a full-frame camera, and roughly a 10-20mm lens on APS-C. It's quite chunky for an MFT lens, at 79 x 106mm and 534g, but still reasonably small for this class of lens, especially when you take the fast and constant f/2.8 aperture into account.
The 14 optical elements include one ED (Extra-low Dispersion) and three Super ED elements, along with two HR (High Refractive) elements. Focusing is entirely internal and, even though the front element extends at wider zoom settings, it remains well within the boundaries of the permanently fixed petal shaped hood.
The angle of view stretches from 75 degrees at the 14mm setting all the way to an impressive 114 degrees at 7mm. To go wider than this, you'd need to look at something like the Olympus 8mm fisheye prime. The 7-14mm can stand up to a wide range of weather conditions as well, thanks to its splash-proof, dust-proof and freeze-proof construction. The typical manual focus clutch and dedicated L-Fn (Lens Function) button are fitted and, overall, 'Pro' line handling feels entirely consistent with other lenses like the 12-40mm standard zoom on test.
The autofocus system is very quick and extremely quiet. Sharpness in the central region of the frame is exemplary, even at f/2.8. As is usually the case with ultra-wide lenses, corner sharpness is less impressive and benefits from stopping down a little, in this case to around f/5.6. Colour fringing is very minimal, whereas the remarkably low barrel distortion at 7mm all but disappears throughout the mid to long end of the zoom range. Given the big areas of sky often captured in ultra-wide shooting, the ZERO (Zuiko Extra‑low Reflection Optical) coatings are another bonus, which do a good job of fending off ghosting and flare.