Hands-on with the Olympus M.Zuiko Digital ED 8-25mm F4 Pro

The Olympus M.Zuiko Digital ED 8-25mm F4 Pro is a compact, ultra-wide to normal zoom lens for the Micro Four Thirds system. It covers a full-frame equivalent range of 16-50mm.
It’s also the newest member of the Olympus Pro lens family, which has a reputation for solid build quality, reliability and excellent optical performance. We’ll take a look at this new lens and what it has to offer on the next few slides.
Design and build

The 8-25mm F4 Pro is built to professional standards. Its all-metal design results in a lens that feels hefty despite its compact appearance. Olympus gives the lens an IPX1 rating, claiming dustproof and splash-proof performance as well as freeze-proof operation down to -10ºC (14ºF). The front element includes a fluorine coating for easier cleaning, and a rear gasket ensures protection between lens and mount.
The design also incorporates a retracting zoom mechanism, the first for a lens in the Pro series, which helps account for the small size. A stiff twist of the barrel is all that’s required to extend the lens to its working position, ensuring it can be activated quickly when needed.

The optical design utilizes 16 elements in 10 groups. It includes various special optics, including one Super ED (extra-low dispersion) and two ED lenses to suppress chromatic aberrations. A DSA (dual super aspherical) element promises to reduce comatic aberrations, which will be appreciated by nightscape, cityscape and astrophotography shooters. In addition, Olympus’ ZERO (Zuiko extra-low reflective optical) coating promises to suppress ghosting and flare, which appears to be pretty effective (YouTube link) in our initial testing.
Our initial testing also shows almost no lateral chromatic aberration (sample image link). Though perhaps visible in absolute extremes of some images, it's completely removed in JPEG and Raw conversions (open this Raw image in Capture One and you'll see a hint of it in the rocks at bottom left with CA correction turned 'off'). Longitudinal chromatic aberration, as expected for a slower lens of this type, is practically absent (sample image). Optical distortion is present on the wide end, but you won't see it because it's corrected for digitally. On both ends of the zoom, central sharpness is great even wide open (YouTube), but corner sharpness does improve slightly upon stopping down a bit.
Video shooters rejoice! The lens is also corrected for focus breathing. In fact, our team at DPReview TV found no visible focus breathing (YouTube) during their hands-on review.

In a move that’s sure to please many users, the lens features a focus clutch that allows for quick switching between auto and manual focus modes. When combined with automatic focus magnification and peaking on Olympus bodies, it provides a quick and effective way of switching to manual focus operation when needed.
The front of the lens features a 72mm filter thread, and seven circular aperture blades aim to deliver smooth bokeh. Our initial tests found the bokeh to be nicely rounded, but bokeh discs have distracting texture (sample image), with a bit of a 'soap bubble effect' due to slightly hard edges. Sunstars, when stopped down, are competent though not class-leading (YouTube), with only 14 rather diffuse spikes. That doesn't mean you can't get pleasing ones under the right conditions (sample image) though. A lens hood is included.
A programmable function button is also available on the side of the lens.

All-metal construction gives the lens some heft, but it still weighs in at a manageable 411g (14.5 ounces). We found that it balanced well on both compact bodies like the E-M1 III and the larger E-M1X.

Though not technically a macro lens, the 8-25mm F4 has some close focusing ability, particularly at the tele end, delivering 0.42x magnification at 25mm. This drops to a magnification ratio of 0.14x at 8mm, however. Close focusing distance is a consistent 23cm (9 inches) across the entire zoom range.
The lens also supports focus stacking on compatible Olympus bodies running the latest firmware.
Hands-on with the Olympus M.Zuiko Digital ED 8-25mm F4 Pro

This lens covers a versatile zoom range, from ultra-wide to normal, and features the solid build we expect from Olympus Pro lenses. Its compact size and collapsible design will likely make it popular among travel photographers, and videographers will love the focus clutch and controlled focus breathing. With a versatile range equivalent to 16-50mm on full-frame, we expect it will fit the needs of many Micro Four Thirds shooters.
The Olympus ED 8-25mm F4 Pro will be available on July 9 for $1099 in the US and $1399 in Canada.