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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  1. Hello Then,

    If I were to choose between panasonic 14-45 mm and olympus 12-50 as the only lens I carry for casual shoot – which one would you recommend?

  2. The photos you took with the 12~50 are indeed dreadful and shouldn’t even be posted. Joking, of course. I assume that you took the same shots with the other prime lenses for comparisons? In RAW as well. No? Hmmmmmmmmmmmmm, As you are obviously a “pixel peeper”, have you actually looked at the tests (MTF, CA, Distortion, etc.) for the fast primes in the micro 4/3rds category? Except for the Leica 20mm F1.7, none of them, including the Summilux 25mm F1.4 perform any better at the same focal length and wide-open aperture as the M Zuiko zooms. Faster? Are you bemoaning not being able to shoot at F1.4? Because in ANY of the shots above I do not believe a larger aperture would have yielded a better shot, and probably yielded instead a loss of DOF. Do you ever factor in the missed opportunity of having to change lenses, or, do you possibly believe that a “prime” is still the answer, yielding better quality when cropped 50% than a shot that was composed and framed in-camera? And as to my credentials to make these comments, I have a Masters Degree in Art/Photography, am a Master Optician in precision optics, and a certified optician in Ophthalmic optics. OK, now I am sorry I ran across this column and the dribble you have written. Perhaps you should start taking pictures of test charts, or perhaps learn that it’s not the camera or the lenses, but the photographer that makes the difference. Oh, an of course there IS post-processing . . . or is that out too?

    • I’m sorry, were you drunk or otherwise under the influence when you wrote this? Satire doesn’t always translate well across the internet.

  3. This is the best review on the Olympus 12-50mm so far. With all its negatives mentioned here, I wonder it still has the redeeming quality of being a good “video lens.”

    In a review for Panasonic’s 14mm http://m43photo.blogspot.ca/2011/01/comparison-lumix-14mm-vs-lumix-20mm.html it was said that a slower lens with larger minimum aperture are better for video because of video’s lower resolution and how diffraction could also “improve” video quality. Would this apply to the 12-50mm too?

    • Lower resolution doesn’t improve video quality, it hides the fact that the lens doesn’t have the necessary resolving power…I still think the two-lens combo is better for video.

  4. “I’ve owned pretty much all of the m4/3 “kit” lenses. I had high hopes for the 12-50, mostly because of it’s relatively high price, but have to agree completely with your review. Adequate but disappointing.”

    Putting aside the fact that the lens is weather resistant and dust resistant, how would it compare to the 14-150 zoom lens?

    This lens is a swiss army knife and I would probably have it handy in case of inclement weather but I also have a storm Jacket handy for the same reason. I have not yet seen the lens produce the optical results that this Omd sensor allows.

    • I can’t say as I haven’t used the 14-150. But I do know that the zoom ring does have hard stops, which would be most welcome. The lack of them on the 12-50 drives me absolutely crazy.

  5. My 12-50mm is like yours, very bad corners at wide angles, especially the right side which is worse than the left (maybe it’s decentered?) but the left side is not especially sharp either. And the softness has a sort of haze about it that is worse than suggested simply by looking at resolution of a black-and-white test chart. The softness extends far into the image; it’s not just an extreme-corner thing. It’s noticeable even at reduced image sizes. For $300 I had higher expectations.

    But the lens does very well at the longer focal lengths, from 25mm to 50mm.

    The lens also has good “wide open” performance in that’s not really much worse wide open than it is stopped down. Although “wide open” with this lens isn’t especially wide open given its slow f/stops.

    • I don’t have the decentering – it’s equally soft everywhere – but yes, the slight haze is bothersome. It appears as a lack of microcontrast here, and blacks that do not quite manage to be black. My copy has the problem everywhere in the range; wide is a bit better than tele, and 50mm is decidedly soft.

      The reason why stopping down doesn’t help is because we’re already hitting diffraction limits by f6.3 on the OM-D’s sensor.

      • Most of my 43 and m43 lenses have improved image quality as you stop down to f/8, so I don’t agree with the f/6.3 thing. And I’ve observed that my m.zuiko 14-42mm II is sharpest at f/9 on the telephoto end (anything past 25mm or so).

        In fact, I think I’m just going to use the 14-42mm II as my main zoom lens from now on. It’s very light, and although when I shoot a black and white test chart, the 14-42mm II doesn’t quite do as well as the 12-50mm, the images from the 14-42mm II somehow LOOK a lot better (now that I’ve learned to stop down). The 14-42mm II doesn’t have hazy corners, and although it’s not super sharp, especially not on the telephoto end, it’s good enough so that you don’t notice anything wrong with the image unless you are viewing it at 100% and looking very carefully.

        • If you have a lens whose sharpness peaks before 6.3, you’ll see softening afterwards (but more DOF). If not, then the increased sharpness may partially offset diffraction til about f13 or so.

          I prefer the 14-42 IIR to the 12-50, actually. Maybe I had a particularly bad 12-50, but the difference between the two is pretty huge – especially as you say, in the corners.

  6. axelpix says:

    The Zoom ring in motor zoom position allows for different zooming speeds depending on the degree of rotation you aply. This turns out to be quite usefull for me. It’s definitely not just a single speed.

    I had to shoot a street fair this weekend in the pouring rain. Something you would never do with any other available m4/3rds lens to date. Just to add another potential use of this lens.

    The biggest concern I have with this lens is the terrible CAs and Olympus’ reluctance to implement an automatic CA correction like almost anybody else does today. This makes the lens completely useless for JPG shooting. But this is something I don’t do anyway. As Lightroom 4 has an automatic analytical CA correction feature, CAs are a non issue for RAW shooters anymore.

    • I think I need to send my lens in to be checked out. You’re the second person who’s mentioned variable speed zooming. Agree on the CA problem; it can be so bad in certain situations that the whole image appears I harp because the different wavelengths don’t focus at the same location.

      The problem with weather sealing is that the situations that typically require it – rain comes to mind – also tend to be dark and best served by faster lenses…

  7. I did not expect to like the power zoom feature but find it works well. Your statement that it is like a rocker switch with one speed in either direction is not correct. Unlike many P&S cameras the zoom speed is easily controllable. I think mine has at least 3 different zoom rates depending on the degree of deflection of the zoom ring.

  8. I’ve owned pretty much all of the m4/3 “kit” lenses. I had high hopes for the 12-50, mostly because of it’s relatively high price, but have to agree completely with your review. Adequate but disappointing.
    The very best of them, and the only kit lens I still use, is the Panasonic 14-45 that came with the G1. I probably just lucked out on sample variation, but it’s excellent at all focal lengths, even wide open. Smaller and lighter, too, and half a stop faster at the long end. And practically free now.
    If you come across one, give it a try.

  9. What would think of the ZD 12-60mm for four thirds with the adaptor instead? Obviously it’s bigger and heavier but it’s f2.8 to f4 and better construction. Do have any experience with it? Thanks for your review and sample photos. Much appreciated.

    • I used one on the E-3; that was an excellent lens, really not in the same league as the 12-50. But it would seem to defeat the point of M4/3 from both a price and size standpoint; it wouldn’t cost much more to get say the 12/2 and forthcoming 60/2.8 macro, which would gain you a stop at each end, faster focusing and macro capability. I don’t think they’d be any larger or heavier, either. However, I tend to be one who uses his lenses at either end of the range, so that may or may not be relevant to you.

      • Yes, the 12mm & 60mm would be very good options on the smaller body. It’s just that I already own the 12-60mm zoom and wondered how the weight and size balance would be on the OM-D. Thanks again.

  10. ordinaryimages says:

    Like you I took this lens with the second E-M5 as an inexpensive knock about lens with splash proofing for rainy days, It’s sits on a shelf near the door set to Macro mode w/L-fn to Magnify, lest an interesting bug wanders by. We’re in a horrible drought so I have yet to have that rainy day experience, but concur with your observations…no soul. Certainly not worth the stand alone price for my uses, whereas the 12 and 45 are very pleasing.

    • I thought there was no harm in trying it since the price difference between kit and body-only wasn’t that much…but it’s since sat unloved, especially with the 12 and 45 lenses.

      • I don’t have this lens – but I have been considering it amongst other contenders as a travel option particularly in light of its surprisingly good macro capability, but that’s another story. What I can’t understand is why you and others bang on with comparisons between it and primes!! Its a totally unfair and inappropriate comparison to make. I think your conclusion about the lens is probably correct, however, making comments like “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” really is redundant.

        • Because it’s not as silly a comparison as you might think. It would take up as much space in your bag as a 14/2.5 and 45/1.8, and cost about the same if bought new on its own. Plus even if you stop it down, it doesn’t even match the sensor that well – let alone the other lenses. Doesn’t make sense as a travel lens for me, either.

      • ordinaryimages says:

        Max I appreciate your sentiments…but having the lens I am not generalizing…the 12-50 is a different bird with a graphical signature. The point is that at the kit price it is a reasonable choice for the splash/dust proofing and Macro possibilities, but I wouldn’t recommend it as an only lens at the “stand alone price”.

      • Steve Jones says:

        Hi Ming. Sorry to disagree just a little bit but I also don’t see the point in making an optical results comparison of the zoom with fast prime lenses. Fast prime lenses will win every time, they’re optimized. I don’t think anyone reading here would really expect the zoom to perform at that level. But I do travel photography ( Not from the comfort of a car but on foot ) and while I can appreciate the superior performance of the primes it is definitely nice sometimes especially when it’s cold, raining, sand blowing around, whatever, to NOT to have to fumble for a lens. That might sound lazy but it’s not. It’s about practicality. I speak from experience and believe me, the ability to cover a useful range in one lens is worthwhile. I have lost great shots or resorted to a compact camera stashed in a pocket because changing lenses wouldn’t have been fast enough. And some of the spots i’ve found myself in taking pictures have been quite precarious, ledges on the side of a mountain where i’ve been balancing a great photo and my life! You’ll think at least twice in that situation about reaching in the bag for the 12 if you unfortunately have the 45 fitted. Also the kit zoom takes really remarkable macro photos, something the 12 and 45 don’t do. If I didn’t have that possibility I’d be needing to carry a separate macro lens. I was dubious about the quality of this lens because of the poor performance of kit lenses on the market. It surprised me. True, as you point out It’s not fast .To a large extent the IS system and good ISO ability of the camera body balance that out. Coming from using film cameras for years where I was stuck with IS0 100-400 to maintain quality I feel spoiled with the range of digital. So I don’t feel that’s a limiting factor. I think if someone buys an OMD camera with kit zoom and a 45mm for low light they’ll be pretty happy with the results. And that 12mm lovely as it is, is mighty expensive for most people costing almost as much as the body alone.
        I can afford that if I choose but I’m finding the 12-50 to be doing just fine for now for general purposes. Posted this here, just to give a different perspective on the lens review and for anyone who is thinking of buying into the system. Sorry if I missed it in your review, but the power zoom on the kit lens works nicely for video too. Many would benefit from that.
        Finally, your own photos show what can be done with the lens by a skilled photographer who knows what he’s doing!

        • Some zooms are pretty close to prime lenses – the Nikon 24-70 is a good example, and some do what even few primes can – the Nikon 14-24 is another such example. If you’re trying to decide between this 12-50 and say a 14 and 45 pair – similar size, and with a bit of hunting on the used market, similar price – the comparison isn’t even close.

          I agree with the convenience aspect – the problem comes when under those dark, cold, wet conditions, f6.3 (and a much lower T stop than that) just doesn’t cut it. I solve the problem by having two bodies – usually a Pen Mini with the secondary lens on it in a pocket and ready to go, and the the other lens on the OM-D. Yes, the improved high ISO abilities and IBIS of the OMD do somewhat negate the slow aperture of the kit zoom, but you have to remember that given the same primes, your shooting envelope would be further extended by a similar amount again.

          No doubt it’s convenient if you just want one lens, and aren’t too worried about chasing ultimate optical quality or having multiple lenses. Most things look fine at web resolutions, at 100% I found very, very few images that were critically sharp.


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