Introduction

Ease of Use

The Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro is a weather sealed lens with a dedicated Micro Four Thirds mount. 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 flagship OM-D E-M1 Mark II that we tested it with.

Tipping the scales at 561 grams and measuring 116.5mm in length and 77.5mm in diameter, the Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro is a substantial zoom lens, but given the constant f/4 maximum aperture, that's perhaps no surprise. When it's zoomed out to 100mm, it measures nearly 16cms in length.

The Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens attached to an Olympus OM-D E-M1 Mark II

The Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens attached to an Olympus OM-D E-M1 Mark II

The Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens attached to an Olympus OM-D E-M1 Mark II

The Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens alongside an Olympus OM-D E-M1 Mark II

The Olympus OM-D E-M1 Mark II used for this test is a great match for the lens, offering good balance, fast auto-focus, and full environmental seals. The M.ZUIKO Digital 12-100mm f/2.8 Pro lens itself is very well built, fully living up to the PRO designation that Olympus have given it.

Front of the Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens

Front of the Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens, extended to 100mm

In terms of features, the M.ZUIKO Digital 12-100mm f/2.8 Pro lens has quite a lot to offer. For starters, it has a so-called L-Fn button, which allows users to temporarily suspend continuous auto focus when something suddenly comes between the lens and your intended subject. This is mostly useful when shooting a movie clip with C-AF enabled, but the feature can also be used when photographing action.

Front of the Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens

Rear of the Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens

The 12-100mm f/2.8 Pro features its own 2-Axis image stabilisation system. It also features Sync IS, which allows it to work with the excellent 5-axis system in any compatible camera body, like the OM-D E-M1 Mark II that we tested it with, where it offers an amazing 6.5 stops of compensation, surpassing any other camera that we've ever tested.

Side of the Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens

Side of the Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens

The Olympus M.ZUIKO Digital ED 12-100mm f/3.5-6.3 EZ lens features a 72mm filter thread and a front bayonet for attaching the supplied LH-76B plastic lens hood, which has one small button 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 on the lens.

The Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens in-hand

The Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro lens with the LH-76B lens hood fitted

The lens comes with a standard Micro Four Thirds mount that is, as you'd expect, made of metal, with a rubber seal around the mount. Communication between lens and camera body is provided through eleven electrical contacts.

Focal Range

The lens has a very 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.

Field of view at 12mm

At the 100mm end, the angle of view is 12°, i.e. the same as that of a 200mm lens in a 35mm system.

Field of view at 100mm

Focusing

With the 12-100mm lens attached to an Olympus OM-D E-M1 Mark II body, focusing is extremely quick in most situations. The camera-lens combo 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, but the constant f/4 maximum aperture nearly always allows enough light to pass through to the sensor.

Manual focusing is done in a traditional fashion, with the generously sized focus ring mechanically coupled to the moving lens elements, complete with hard stops at either end. The lens also usefully features a distance scale, which is cleverly revealed by pulling back the Manual Focus Collar to instantly engage manual focusing. Like zooming, focusing is fully internal and the filter thread does not rotate on focus.

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 at f/4, which you will probably not even notice in your real-world photos, and distortion is commendably kept well under control too.

Vignetting at 12mm

Vignetting at 100mm

Macro

The Olympus M.ZUIKO Digital ED 12-100mm f/4.0 IS Pro is actually a fairly good macro lens, offering a minimum focusing distance of 15cm and a maximum magnification of 0.3x at the 12mm wide-angle setting and 0.21x at the 100mm telephoto setting. The following example demonstrates how close you can get to your subject with the lens set to 100mm, in this case a Compact Flash memory card.

Close-up performance

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 12-100mm f/2.8 Pro, Olympus employed a seven circular-bladed diaphragm, which produces some very 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.