It occurred to me, as I was sitting ponderously at my desk recently, that while I have had the Olympus 12-40mm f/2.8 PRO lens for over a year, I have still not written a review of it. Considering the absolutely top-notch quality of this general purpose lens it’s something of a massive oversight and I do apologise to the Olympus users who visit this site in search of insights into the gear I am using that I haven’t yet posted my “official” opinion of it. Better late than never, so here goes!
The Futile Argument Of Equivalence
OK, so most of the world’s photographers who are interested in micro four thirds will already know that this is a general purpose zoom lens for the system that covers the most commonly used angles of view, from moderate wide angle to moderate telephoto. Those using the 135 system will obtain a similar angle of view from a 24-80mm lens. Those using APS-C sensor systems like Fujifilm will be more familiar with the 18-55mm lens for this view.
Those lenses all give a similar view but the larger sensors will give you a shorter depth of field when used at the widest apertures. Some arguments point to a 2 stop difference between 35mm systems and m43 systems, so the proponents of larger sensors will insist on stating that the 12-40mm f/2.8 m43 lens is only equivalent to a 24-80mm f/5.6 lens on that larger system. Anybody who knows anything about photographic exposure will quickly debunk this assertion because aperture controls not only depth of field but also exposure. You will get the same exposure under the same lighting conditions by using either an 24-70/2.8 or 12-40/2.8 lens.
A 24-80mm f/5.6 lens cannot shoot at f/2.8 therefore it cannot be considered “equivalent” to a lens with an f/2.8 maximum aperture. The only characteristics it would share with such a lens are the depth of field seen when each is at its widest aperture. The equivalence theory goes out the window when you look at the comparative shutter speeds that would be required by each lens to make the same photo at their respective maximum apertures. The f/5.6 lens will need a four times slower (2 stops) shutter speed to make the exposure. Consider the f/2.8 lens showing a shutter speed of 1/30 second at f/2.8. The “equivalent” f/5.6 lens will need 1/8 second to make the same shot under the same light. Not so equivalent after all, is it?
So, the only difference in the images these two f/2.8 lenses will create will be evident in the depth of field between them. The smaller lens will have more of it and the bigger lens will have less of it. How much less? Not really that noticeable when you are standing quite far away from the final image, be it printed or displayed on a screen. If you have a 24-70/2.8 lens stop it down to f/5.6 and look at what happens when you press the depth of field preview button.
Right, so we’ve got that out of the way and hopefully put to bed the silly notion that we are looking at a 24-80mm f/5.6 lens in this review. We’re not. It’s a 12-40mm lens and it's f/2.8 all day long.
The Cosmetics, Build Quality & Features
When I first opened the black box that transported this lens safely into my hands it became very evident that Olympus have gone the whole hog with not only packaging presentation, but also the design of this lens. It’s solid. It’s bold in black. It has milled ridges on the focus and zoom rings, no rubber bands. It comes with a lens hood! There is a felt pouch for storage too. The lens cap has a new design and has a metal ring around it. There is a designated function button on the barrel that can be programmed to accept any number of Olympus custom functions. I can’t really find a function that is lens specific other than enabling the digital 2x teleconverter, so that’s what mine is set to.
The logo and designation on the barrel appear to be engraved, not printed. It looks and feels like a lens that might have been made in an age when craftsmanship was something camera manufacturers all aspired to. Very handsome indeed.
The 12-40mm is the first of Olympus’ PRO line of lenses. It’s weather sealed, so you can use it in a downpour (please don’t pour water on it like some crazy people have been doing to test this - it’s not waterproof, it’s weatherproof and there is a difference).
There is one thing about this lens’ design that almost saw me sending it back before I had a chance to properly use it. When I put it on my E-M1 it was stone dead in the auto focus department. I checked the contacts on the camera and the lens. No dirt, no grease. I put it on the E-M5. Same thing. The cameras both acknowledged the presence of the lens and I could adjust apertures, meter properly and take shots, but I just couldn’t get it to auto focus.
Despondently I packed in back into its sexy little box and wondered if I had made a mistake buying into the brand, because this was surely the lens I would be using the most. If it had an out of box failure how could this be a good thing? A few hours of stewing in my own juices passed. I took it out again, put it back on the camera. Same deal. No auto focus. I think I must have repeated this at least three times, hoping, praying that there would be a different outcome (yes, I have been called insane by others many times).
Eventually I thought it might be a good idea to read the inserted paper manual thing that came in the box (this was a first for me). Lo and behold, my problem became apparent immediately. No, it wasn’t insanity. The lens was shipped in manual focus mode! There is a clutch mechanism built into the focus ring that slides it between the two modes. In MF mode you will see a distance scale printed on the barrel. Bloody hell, Olympus! I can’t but imagine the number of people who have been caught out by this and sent back perfectly normal lenses thinking they were broken. I know of at least two other FZ members who encountered the same thing and told me about it.
Anyway… how does it handle everyday use?
Auto Focus Performance
Once I had finished berating myself for not being properly thorough with my lens inspection the first time around, I set about testing the auto focus. Well, to say that I am impressed with the speed of autofocus would be an acute understatement. This is probably one of the fastest focusing lenses I have ever used. It can shift focus from infinity to 20cm away in a split second. And it is very, very accurate. Continuous autofocus is pretty decent too although in honesty I don’t use this mode because the AF-S is so fast to acquire focus that all I do is repeat press the shutter button and it locks on immediately (I don’t use the AF-on method if you were wondering). I very seldom find myself using this lens for the kind of stills photography that requires tracking of moving subjects so I haven’t got a lot to say about that in this review. I have made one or two videos using the AF-C mode and it works perfectly well.
My wife hates this lens. She already cringes and rolls her eyes when she sees me pointing a camera in her direction but now when she sees this lens coming she throws in a few choice verbs to her protestations against having her photo taken. It’s a very sharp lens and my better half is on the other side of 40, so I am constantly compelled to use negative clarity in processing if I ever manage to get her to sit for a portrait.
Prior to moving to the m43 system I was using a Nikon D700 with the Nikkor 24-70mm f/2.8 as my main combo for a variety of professional jobs. I loved that combo to bits because it made my job so easy. It didn’t miss a beat. I never thought I would ever part with that lens and I often referred to it as the best zoom lens I had ever used. And then along came this Olympus lens. It had very big shoes to fill, but I will tell you this: in spite of its comparatively diminutive size, I find it is a better lens all around than the Nikkor. This is a strong statement to make and I can hear the collective gasps from users of that Nikkor ready to pounce on me and demand proof as they point to various charts and other scientific data, all of which rolls off my back as easily as water off a duck’s rear end. I’ll say it again; for me the Olympus 12-40mm is a much better lens than the Nikkor 24-70mm.
The Nikkor I found a bit soft at f/2.8, while the Oly is sharp everywhere. I can’t tell any difference in sharpness from the widest aperture all the way through to f/14 (which is where I usually use it in studio product photography). It’s decidedly faster to focus than the Nikkor and there is the small matter of size to consider. The Nikkor positively dwarfs the Oly. I think you could fit the Oly into the lens hood on the Nikkor.
The proof of the pudding as far as performance goes is in the eating and I have had over a year of yummy photographs in a multitude of situations to keep me extremely satisfied with this lens. In fact, I am so satisfied with it, that it has kept me from even looking at the faster prime lenses that are available for m43, such as Olympus’ 12mm f/2.0 and the 17mm f/1.8. This lens just works for me and apart from possibly getting shorter depth of field with the primes, I see no advantages in having them for the kind of work I find myself doing. Changing lenses would just slow me down on a job, besides, compared to what I was using, the size of this lens is insignificant for a full day’s shoot. Others may prefer the primes and I am by no means saying that this lens is better than them, just that it is so good that I can’t imagine the primes being anything more than a hassle for me to use.
Flare, Distortion and Other Stumbling Blocks
This will be the shortest part of my review. I can’t make any negative comment about this lens with respect to any of the things that would usually cause a prospective buyer to think twice about a lens purchase. Nothing in my day-to-day professional use of this lens for over a year has presented itself as a problem. I’ve used it at corporate events, live shows, family gatherings, product photography, headshots, reportage, etc. It just does it all well.
As I mentioned in the beginning of my review, the only negative thing I have to say about this lens is that the AF/MF clutch mechanism can catch you out. It’s done it to me a few times already, to the point where now I am acutely aware of it should I suddenly find myself wondering what happened to the snappy AF. It’s pretty easy to shift too, so hopefully if Olympus’ designers are ever going to update the lens they will make sure to either stiffen this mechanism up a little or at least revert to using a traditional switch. Personally I have no use for manual focus so if they excluded it completely it wouldn’t be a problem for me.
The other option is the Panasonic 12-35mm f/2.8 which comes with built-in stabilisation, but I don’t have any experience with that lens so I can’t make any comment on how it compares to this one. I have read good things about the Panny so I think Panny users would probably be better off with it than the Oly purely because of the stabiliser on the lens. If you are an Olympus user and you are looking for the best general purpose zoom lens for your system you will not be disappointed with this one. It ticks all my boxes and I must give it a 5 star rating. It is the best general purpose zoom lens I have ever used.
Here are some samples from my year of use. Click to enlarge.
Shooting directly into the sun - images used in a brochure for the light post manufacturer
Not quite direct sun but shot through a window of my house
Depth of field at close range is short enough for me.
Subject isolation and bokeh is pretty good.
Image shot for a client's corporate profile photo.
Shot for a website project I just finished recently.
Shots for DAAD at a local university (they recruit foreign students to study in Germany).
Handheld night shot at the AIMS Congress farewell dinner at the Moses Mabhida stadium.
Product shot in studio at f/14. Diffraction limits?
Christmas in Africa - I even use it for personal work.