Olympus M.Zuiko Digital ED 12100mm f/4 IS Pro
Olympus has made probably the best superzoom lens on the planet, says Andy Westlake
Andy Westlake tests the best superzoom around
It’s widely understood that cameras with larger-format sensors should give better results than those with smaller ones, and that fixed-focal-length prime lenses are sharper than zooms. When we compare zooms, those with relatively short 3x ranges are best, while ‘superzooms’ with zoom ratios of 7x or greater require considerable optical compromises to achieve their range.
So what are we to make of Olympus’s 12-100mm f/4 lens, launched alongside the firm’s flagship OM- D E- M1 Mark II at the end of 2016? It’s an 8.3x superzoom for Micro Four Thirds cameras, which have sensors somewhat smaller than the common APS- C format found in most enthusiast DSLRs and mirrorless cameras. Surely this must be a marriage made in hell, at least in terms of image quality? Well, sometimes it turns out that what we think we know is wrong. The giveaway that things are different here is in the lens’s name, not to mention price. The ‘Pro’ designation means it’s in Olympus’s top line, with premium optics and weather-sealed construction. Meanwhile, the £1,100 price tag suggests the firm hasn’t skimped in solving the problems posed by such an ambitious design. To cut a long story short, the result is probably the best superzoom ever made.
Features
The 12-100mm is one of a handful of such lenses starting at a 24mm equivalent, compared to the more usual 28mm; in return, it extends less far at telephoto. The closest comparable optic is Sony’s FE 24-240mm f/3.5- 6.3 OSS for full-frame mirrorless, but at £750 it has less lofty ambitions.
An indication of how unusual the lens is lies in its optical formula, which comprises 17 elements in 11 groups. But this includes 12 special elements: three aspheric elements, one dual-sided aspheric (DSA), one element made of high-refractive (HR) index glass and two of Super HR glass, and five of extra-low dispersion glass. Olympus has also employed its Z Coating Nano to reduce flare and ghosting.
The lens boasts a minimum focus of just 15cm at wideangle. More practically, it’s still capable of focusing on an image area of around 82x62mm when set to 100mm, giving a magnification equivalent to 0.42x on full frame. A petal-type lens hood is included, and the lens accepts 72mm filters.
The really big deal, though, is the addition of optical image stabilisation. This is only Olympus’s second lens to feature this; previously, the firm has relied on in-body
stabilisation. It makes the 12-100mm an attractive option not just to Olympus users, but also to owners of older Panasonic cameras that don’t include in-body stabilisation.
Crucially, though, the lens is compatible with Olympus’s Sync IS, in which optical stabilisation and the in-body sensor-shift stabilisation work together for increased overall effect. As a result, when used on the flagship OM- D E- M1 Mark II, the system is rated to provide an improbable-sounding 6.5 stops of stabilisation. With older OM- D and PEN cameras, the stabilisation won’t be quite so marked.
Build and handling
The 12-100mm is built to essentially the same pattern as Olympus’s other Pro lenses, with a tough metal barrel that’s sealed against dust and moisture. It has finely textured zoom and focus rings, and accented rings around the barrel in gunmetal and blue. A couple of ridged barrel sections next to the mount provide extra grip for mounting and removing the lens.
With a 77.5mm diameter, length of 116.5mm and weighing 561g, this is one of the largest lenses in the Micro Four Thirds system. It’s a good fit for high- end bodies such as the E- M1 Mark II or Panasonic G9, but on smaller cameras it can feel somewhat front-heavy. Owners of E- M5 and E- M10 series cameras may prefer using it with an accessory grip.
The zoom ring falls perfectly to hand, and rotates through about 90° from one end of the range to the other. In front of it is the dualmode manual-focus ring (more on this later). On the side of the barrel is a very large image- stabilisation switch; potentially confusingly, this controls both the in-lens and in-body IS systems simultaneously, so switching it off disables both. Below it is an L- Fn button, which interrupts AF but can be reconfigured to operate other functions such as depth- of-field preview.
Autofocus
When it comes to static subjects, the lens focuses quickly, accurately and silently, regardless of the focus distance, or where you place the subject. Likewise with continuous AF, the lens kept up with whatever the E- M1 Mark II asked of it during testing, holding focus on moving subjects at 10fps or faster.
For manual focusing, the lens is equally well behaved. As with Olympus’s other Pro lenses, pulling the focus ring back towards the camera enters MF mode, revealing a distance scale, and with hard end stops to its travel. Alternatively, if you switch the camera body to MF mode, the focus ring can operate in a focus-by-wire mode, which I found offers finer adjustments. The lens behaves as if it is parfocal, that is, the focus distance doesn’t change as you zoom; this is achieved by the lens automatically adjusting the position of the focus group.
Performance
So how does the lens perform in real-world use? This is where things get interesting,
‘With this lens, I’ve shot handheld at speeds as long as four seconds’
because the 12-100mm f/4 IS gives unusually fine image quality for a long-range zoom. Coupled with its implausibly effective image stabilisation, this turns it into a unique and really useful photographic tool.
Optically, it’s impressively sharp across the frame at all focal lengths, with just a little smearing in the corners at the wideangle setting. It’s pretty much at its sharpest wide open, but I’d avoid using apertures much smaller than f/8 due to diffraction softening. Unusually, it’s nearly as sharp at its minimum focus distance as it is for more distant subjects.
As usual with Micro Four Thirds, chromatic aberration and distortion are automatically corrected in software, so you won’t see much hint of either in normal use. Vignetting is too low to be of any practical consequence.
With its f/4 maximum aperture, this lens isn’t going to be your first choice for shooting with shallow depth of field: it’ll give similar results to using f/5.6 on APS- C or f/8 on full-frame in this respect. But you can still get attractively blurred backgrounds, particularly when shooting close-ups and towards the long end of the zoom.
It’s the image stabilisation, though, that sets the 12-100mm apart, at least when used on current Olympus bodies. With other IS systems, I wouldn’t usually expect to get sharp images at shutter speeds longer than 1/2sec; with this lens, I’ve shot handheld at speeds as long as four seconds and achieved perfectly usable results. This does demand optimum shooting conditions and good technique, but incredibly, it really works. Crucially, it means that when shooting static subjects in low light, you can continue to use low ISOs where you’d have to raise the sensitivity considerably on other cameras. This in turn means that despite the camera’s smaller sensor, you can get at least as good or better overall image quality.