A Lens Review, the Olympus 12-40mm f/2.8 lens

The Olympus 12-40mm f/2.8

Here we go! bear with me as I gradually flesh out this review of the Olympus 12-40mm f/2.8 Micro Four Thirds lens. I’m looking for a compact, large aperture lens, with solid build quality and consistent performance. I think the 12-40mm lens should meet these needs, I have recently borrowed the lens so that I can be certain before I spend a whole bunch of money on it!

When first started using the Olympus and Panasonic Four Thirds digital SLR system, Ideal aspirational lenses for me were the large-aperture HG and SHG lenses in the Olympus system. I dreamed of owning amazing lenses like the awesome SHG 14-35mm f/2.0, the super versatile HG 50-200mm f/2.8-f/3.5 but I couldn’t afford them. I found a great deal on the Olympus 11-22mm f2.8-3.5 lens. It produced so many great photos

After a few years and relocating to the other side of the world, I was not using the 11-22 often and decided to cut back to . The focus speed on my micro four thirds body was horribly slow, the weight and size of an SLR lens on a CSC camera with adapter was impractical, eventually I decided to sell the  lens.

Right now i’m shooting all photos with only a Panasonic 20mm f/1.7 and an Olympus 45mm f/1.7. These are excellent lenses and I’ll definitely hang on to them but I need something else, something more versatile. I have realised that I miss owning a high quality, wide angle zoom lens.

Panasonic 20mm and Olympus 45mm

This review will be fairly low on technical details, I don’t have any MTF charts to post, I’m not going to examine vignetting, distortion or comment at all on the colour rendition of this lens. Stay away pixel peepers this aint the article for you 🙂

My thoughts on the 12-40mm f/2.8

I’m looking to branch out more and get a lens more versatile for all types of shooting and the 12-40mm should suit that perfectly. On paper the specifications read like something perfect for an all-rounder lens, given that you still want something reasonably compact… For an all rounder lens options like the 12-100mm look outstanding, but I would like the larger f/2.8 aperture for low light and depth of field control, additionally the 12-100 f/4 IS is substantially larger and more expensive.


The lens has a wide angle of 12mm and a telephoto 40mm and has the equivalent field of view as a 24 to 80mm in 35mm ‘full frame’ terms. It’s not often that I would need to go wider than 24mm equivalent, but if you take interior architecture shots your experience may be very different. This range is such a useful range for me, It probably covers 85% of the kind of photos that I take.

Zoom focal length range for Olympus 12-40mm F/2.8


I even found the long end of the 12-40mm was excellent for portrait shots unless I want a better control of that background blur/bokeh, in that case I would reach for my Olympus 45mm f/1.8. But, the closer focusing distance of the 12-40mm gave me a bit more flexibility when framing and working much closer with a subject.



The first thing that you notice when picking it up, is that for a relatively small lens it is quite heavy. The weight of of the lens is 382 grams. It’s about the physical size of a standard kit lens for an APS-C Digital SLR, with maybe a tiny bit added to the length. It’s almost all metal with some plastic rings and covers on certain elements, The feel of the lens is definitely premium, which is important for a lens marked out as a ‘PRO’ lens in Olympus’ range.

Olympus 12-40 f/2.8 from all angles

The lens is arguably a little big to mount on a smaller micro four thirds body, you’d generally find it to be a little front heavy. Mounted on my OMD EM5 without the grip isn’t too bad as the EM5 is has a reasonably weighted metal body, but for anything smaller and lighter you may find it to have slightly awkward handling. Once I had the extra grip and battery attachment it felt just right.

The lens on my Olympus EM5


The 12-40mm is weather and dust sealed as long as you use it with the appropriate weather/dust sealed CSC cameras from the micro four thirds range. Another important thing to keep in mind with weather sealed camera gear is that whilst it is designed that way from new, sometimes age and use can affect this ability. If you have a well worn weather sealed camera body make sure it stays that way, keep it clean and dry when not in use and it’s generally recommended to have these cameras serviced by the manufacturer every couple of years, depending on use.

weatherproof rain on glass

I wouldn’t have any qualms about using my OMD EM5 together this lens in the rain, snow or dust storm. I have seen both the Olympus four thirds Digital SLR system and the more recent micro four thirds system get put through all sorts of abuse and come out the other end functioning perfectly.


The 12-40 has an additional ‘L-fn’ customisable function button on the barrel which using Olympus cameras allows you to set to any number of functions. I didn’t make much use of this but potentially would on a longer telephoto lens if i was shooting sports or fast moving wildlife.

LFn-button on Olympus 12-40 f/2.8


In all my testing I have found the autofocus to be fast, accurate and very reliable. The occasional misses that i have experience was on the Olympus EM1 ii camera on the very far left and right side focus points. Only occasionally, in slightly lower light but still with some obvious contrast in the area of focus, the camera and lens will fail to lock focus. This was only briefly an issue in a couple of situations and I was still very impressed by the accuracy and reliability of the focus system.

I didn’t try any tracking or continuous focus shots, I don’t generally use autofocus in video and given the focal length of this lens I didn’t feel the need to test birds in flight or any sports photography.


The area that particularly impressed me was that the minimum focus distance at both wide angle and telephoto is only 0.2 metres. This flexibility in focus distance is very handy for close up, almost macro level photos. In my use of the lens I don’t think I ever felt limited by the focus range, This usually is something that I really struggle with on wide zoom lenses like this.


Another handy feature is the pull back focusing ring to access manual focus. I used this extensively for both video and photo modes, It’s very freeing to be able to switch quickly between manual and auto focus without fiddling with buttons and a menu system.

12-40 f/2.8 Manual focus ring


I will not write too much on image quality, so many other sites have featured such detailed reviews on this lens, which is a large reason why i’m considering it as a good lens upgrade option for me.

I would rate the detail in photos captured with this lens as excellent. You’ll get the best detail and sharpness somewhere in the f/4 to f/8 aperture range, when setting the lens to f/4 the shots are very sharp and I would comfortably shoot right down to F/11 before the diffraction starts really affecting the detail in your shots. I’m more than happy with the lens’ wide open performance at F/2.8, but your expectations may vary? the corners of photos are slightly softer at the largest aperture setting.


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