Lens review: The Olympus M.Zuiko Digital 12-50/3.5-6.3 EZ for Micro Four Thirds

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Olympus’ latest zoom covers a useful 24-100mm equivalent range (12-50mm actual) and is the kit lens accompaniment to the OM-D in most parts of the world. (I’ve also seen a variant that includes the 14-42 IIR instead.) It’s a bit of a Swiss army knife – the lens has a power zoom feature for video, which can be decoupled to provide a mechanical zoom ring (more on this later) plus a fixed focal length macro mode, at 43mm. It’s also got a programmable function button on the lens barrel. Like all M4/3 lenses except the 12/2, the lens is focus-by-wire only and has a continuously turning focusing ring that has no DOF markings.

Lens and optical formula. The various colored elements represent different types of glass. Image from Olympus Malaysia

Construction is all plastic, except for the metal mount. It’s pretty solid, though the plastics used feel a notch below those in comparable Nikon kit zooms; still, the lens is weather sealed and is the first of the Olympus lenses to feature a rear gasket. It’s not a small lens, by M4/3 standards – it’s about the same physical size as the Voigtlander 25/0.95, but nowhere near as heavy or well built. The best comparison I can give is to one of those miniature cans of mixers they give you on an airplane to go with your shot of whiskey. Like all Olympus lenses, it doesn’t include a hood or pouch (shame on you, Olympus).

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This lens is not meant for low light. This shot – 1s at ISO 800 – says more about the IS capabilities of the OM-D than anything else.

All images in this article shot with an Olympus OM-D E-M5, and the 12-50/3.5-6.3 EZ lens. Clicking on any image will bring you to the flickr landing page, where you and see larger versions.

Optically, the lens uses a 10/9 construction with several exotic elements; with aspherical elements, ED elements, HR elements, and one mysterious DSA element – I think it’s a double aspherical, but it could also be a Japanese government agency. Zooming and focusing is all internal. A quick note on the former: zooming can be accomplished by servo – in the intermediate position, the zoom ring turns into a rocker switch, with one speed in either direction – or mechanically, by pulling it backwards.

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Just your average youth on Saturday

The mechanical zoom is my preference, except in this case it has no real clear stops at either end – so when you turn the camera on, it’s very difficult to tell in advance where you are exactly in the zoom range. The complete lack of external cues doesn’t help, either – there are no focal length markings, and the lens doesn’t change length. I find this very disconcerting, not to mention costing valuable seconds when trying to get a shot.

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The good news is that focus speed is excellent – just as fast as any of the other Olympus ‘MSC’ lenses; I’m told that the system uses some form of magnetic solenoids and a single moving element to keep things silent and fast. Whatever technology used, it’s fast and precise, and has no problem moving in small increments to match small changes in subject distance.

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A bonus feature is a 1:3 macro mode – this covers a 36x48mm frame area at a near focus distance of 20cm (normal minimum focus is 35cm), which actually makes it pretty handy at a pinch. Optically, performance is surprisingly good too in this range – completely at odds with one’s expectations for a zoom-with-macro. The macro mode is accessed by holding down a mechanical interlock button on the side of the lens and sliding the zoom ring all the way forwards, which locks the focal length at 43mm.

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Urban geometry

You’ll notice I haven’t said much about optical performance up to this point. That’s because it’s honestly quite a mixed bag. It can be good – if you stop down a little (though not past f8, because diffraction starts to rob you of resolution by that point) – but not in the corners. The 12mm end comes close to the 12/2 in the center, but is very soft in the corners; actually, soft is not the right term, the resolution is there, but there’s very clear CA causing apparent softness due to the separation of the blue and red components in the image. It’s a similar story at the 50mm end, though not as pronounced in the corners. There’s some internal flare that creates slight haloes around contrast edges, and it lacks the crispness of the 45mm. In fact, the 45mm at f1.8 is sharper than the 12-50 ever gets.

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Waves overhead.

Personally, I find the biggest problem to be not the lack of sharpness, or resolution, or CA – but the poor microcontrast. Textures are not very well defined at all; there’s a decent amount of macro contrast, but overall, the images produced just feel blocky – things seem to fall into either highlights or shadows, and nothing much in the middle.

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The Canyon

All that said, it does pretty well for a kit lens – though personally, I actually think the 14-42 IIR actually performs a little better overall; it just feels like it’s got more ‘bite’ than the 12-50. I could of course have a bad copy. Finally, you’ve also got to watch out for the small maximum aperture; f6.3 on the long end is not bright at all. However, thanks to the relatively small number of elements, the lens’ T stop seems to be fairly close to its f stop.

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Night crossing.

I struggle a little with the conclusion on this one. It’s a lens that is convenient, and does so many things; but at the same time, I don’t feel like the optics do the OM-D’s sensor justice at all. However, if you’re out in the sunshine, and only want to carry one lens, it’s a good option.

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I purchased the lens as part of a bundled kit with my second OM-D; the price difference was quite small compared to body-only; certainly much less than the cost of the bare lens alone. This in my mind made it a worthwhile experiment; however, I don’t think I’ll be using it much, unless I happen to go to the beach or skiing or some other bright environment where I’d rather not be changing lenses. So, if you’d like the convenience, or can’t find a body-only OM-D, it’s not a bad buy; but if you’re expecting it to come close to the resolution of the M4/3 system’s primes, you’re going to be disappointed. MT

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A lens like an umbrella: take it just in case.

The 12-50 is available here from B&H in black or silver.


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