Introduction

Ease of Use

The Olympus M.Zuiko Digital ED 12-45mm f/4 Pro is a weather sealed lens with a dedicated Micro Four Thirds mount that is made of metal, with a rubber seal around the mount. Communication between lens and camera body is provided through eleven electrical contacts.

Note however that in order to take full advantage of the weatherproofing, you will need to mount it on a similarly sealed body, like the new flagship OM-D E-M1 Mark III that we tested it with.

Tipping the scales at a mere 254 grams and measuring 70mm in length and 63.4mm in diameter, the Olympus M.ZUIKO Digital 25mm f/1.8 is a very compact and lightweight standard zoom lens. When it's zoomed out to 45mm, though, it does gain another 2cms in length.

The Olympus OM-D E-M1 Mark III used for this test is a good match for the lens, offering good balance, fast auto focus, and full environmental seals. The smaller E-M5 Mark III camera is probably the best Olympus body to pair it with in terms of overall size and weight.

The M.Zuiko Digital ED 12-45mm f/4 Pro lens is very well built, fully living up to the PRO designation that Olympus have given it.

In terms of features, the M.Zuiko Digital ED 12-45mm f/4 Pro is a lot simpler than the bigger, faster 14-40mm f/2 Pro lens.

As with all Olympus M.Zuiko lenses, the 12-45mm f/2.8 Pro does not offer image stabilisation. Instead this is provided by the camera body, in this instance the frankly amazing 5-axis system in the OM-D E-M1 Mark III, which provides 7 stops of compensation when paired with this lens.

So while the lack of in-lens image stabilisation is a non-issue for Olympus camera owners, other manufacturers who don't offer in-camera image stabilisation in some of their cameras, like Panasonic, may want to consider a different lens.

With the 12-45mm lens attached to an Olympus OM-D E-M1 Mark III body, focusing proved to very quick in most situations. This combination is capable of locking focus on a subject almost instantly, even when alternating between close and faraway subjects.

In extreme low-light situations you may experience a little focus hunting at the long end, where a lens with a faster f/2.8 constant aperture would help avoid this.

Manual focusing is done in a traditional fashion, with the adequately sized focus ring mechanically coupled to the moving lens elements, although there are no hard stops at either end. Focusing is fully internal and the filter thread does not rotate on focus.

The Olympus M.ZUIKO Digital ED 12-45mm f/3.5-6.3 EZ lens features a 58mm filter thread and a front bayonet for attaching the supplied LH-61G lens hood, which twists into place to lock and release it from the lens. The filter thread does not rotate on focus, which is great news for anyone intending to use a polariser or ND grads.

Focal Range

The lens has a versatile focal range. At the 12mm end, the diagonal angle of view is 84°, i.e. the same as that of a 24mm lens in a 35mm system.

12mm

At the 45mm end, the angle of view is 27°, i.e. the same as that of a 90mm lens in a 35mm system.

45mm

Chromatic Aberrations

Chromatic aberrations, typically seen as purple or green fringes along contrasty edges, are only really noticeable by their almost complete absence from our test images.

Light Fall-off

There is only a minimum of light fall-off in the corners, which you will probably not even notice in your real-world photos, and distortion is commendably kept well under control too.

12mm

45mm

Macro

The Olympus M.Zuiko Digital ED 12-45mm f/4 Pro is actually a pretty good macro lens, offering a minimum focusing distance of 12cm at 12mm and 23cm at 45mm and a maximum magnification of 0.5x at both ends of the zoom.

The following example demonstrates how close you can get to your subject. As you can see, if you set the lens to the maximum 45mm telephoto focal length, you can actually fill most of the frame.

Flare

Flare is a typical problem with wider-angle lenses, so we were curious to find out how the Olympus M.Zuiko Digital ED 12-45mm f/4 Pro fared in this respect.

As these examples show, the lens is very susceptible to flare when shooting directly into the sun, even with the supplied lens hood fitted.

Sunstars

The Olympus M.Zuiko Digital ED 12-45mm f/4 Pro produces quite nice sunstars when stopped-down to f/16 and f/22, as shown above and below.

Bokeh

Bokeh is a word used for the out-of-focus areas of a photograph, and is usually described in qualitative terms, such as smooth / creamy / harsh etc.

In the M.Zuiko Digital ED 12-45mm f/4 Pro, Olympus employed a seven circular-bladed diaphragm, which produces quite nice bokeh, at least in our opinion.

However, recognising that bokeh evaluation is subjective, we have provided a few examples for your perusal.

Sharpness

In order to show you how sharp this lens is, we are providing 100% crops on the following pages.