Olympus M.Zuiko 12-40mm f/2.8 PRO: Professional Level Wide-Angle

Olympus M.Zuiko 12-40mm f/2.8 PRO image-3

Olympus M.Zuiko 12-40mm f/2.8 PRO DEALS

The Olympus M.Zuiko 12-40mm f/2.8 PRO was the first offering which was part of the line up to provide pro-level lenses, covering a wide variety of focal lengths. The idea was to cover the most obvious of pro criteria, such as excellent optics, weatherproofing, and high build quality.

By weatherproofing, Olympus uses the term ‘splash proof’ which means it should be resistant to mild downpours, dust or reasonable levels of cold. Thus, let’s dig in and see what this wide-angle zoom is all about.


As for the basic specifications, the Olympus M.Zuiko 12-40mm f/2.8 PRO fits the Micro Four Thirds format on Panasonic or Olympus bodies and is built with a solid construction, ready for most weather conditions. On the inside of the lens, there is an aperture range of f/2.8-f/22 with 14 elements in nine groups.

As this is for Micro Four Thirds cameras, the equivalent focal length works out to be 24mm-80mm. Still relatively wide-angle and arguably covers the traditional range of 24-70mm on most workhorse lenses. There’s also a seven-blade aperture within, which will do the job, but it would have been a nice addition to bump this up to nine blades for more rounded highlights.

Olympus M.Zuiko 12-40mm f/2.8 PRO image-2

The outside of the lens, starting upfront has a 62mm filter thread which can fit an LH-86 petal-type hood. It also doesn’t rotate when zooming, which means you can fit a variety of filters to your liking.

The focus ring has a pullback action that reveals zoom markings and you can also flip the lens into manual focus mode, which also shows a focus scale. The lens also has the benefit of a close focusing distance of 0.2m, which isn’t exactly macro territory, but still very respectable.

As for other outside lens features, there’s the L.Fn button which can be programmed by the camera. Unfortunately, the lens doesn’t have any image stabilization, which is handled internally on Olympus bodies, but for Panasonic users, this could be especially something to note when deciding. The total weight of the lens is a respectable 382g.

Overall, this is a well built and solid feeling lens. Something that initially feels of quality.

Olympus M.Zuiko 12-40mm f/2.8 PRO in Use

The focus ring clutch system is something you need to get used to on this lens. When you move the focus ring back you can easily flip the thing into manual focus mode. This can also happen when the lens is being held downwards. In other words, you need to be mindful of the specific workings of this lens and always make sure autofocus is engaged when you need it.

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When it comes to the overall sharpness, the center is generally very sharp across-the-board. The least amount so at the 40mm end of the spectrum and it still keeps sharpness levels when you’re letting in the most low light at f/2.8. As for edge softness, the attributes below will have an impact, creating some softening of the edges, with this being most apparent at 12mm. At 40mm, there is clearly a little edge softness, but still surprisingly good.

Contrast levels start to drop off at f/5.6 and above, with the best working zone being f/2.8 to f/4. This means that this lens prefers to be wide open than anything else, with probably f/4 being the sweet spot.

Both the zoom and the aperture ring rotate very smoothly, with a slightly different texture on both for easier location when going by feel. Both rings sit very close together, so it does take a bit of familiarity before you get used to exactly where they are located. The L.Fn button is nicely located, within easy reach when both in portrait and landscape positions.

As for general distortion levels of the lens, it does suffer from some linear distortion, especially at the widest focal length. Things do start to clear up around 40mm. This means you’re going to have to do digital lens correction in postprocessing.

The lens shows quite a bit of vignetting when wide open at 12mm. This does reduce significantly at the more telephoto end, but at least the effects are pushed into the corners and could be a positive on the right subject matter.

Bokeh is something you can achieve with this lens, especially at f/2.8, but its usually not at the top of your list with a wide-angle zoom. However, the rendering is down to the seven-blade aperture, which does a relatively reasonable job, but you shouldn’t be expecting the creamy backgrounds you would achieve from a high-end, f/1.4 prime or similar.

Chromatic aberration is kept under good control with this lens. It’s most visible at 40mm when the aperture is fully wide open, but this can be easily taken care of when postprocessing. This all means that you’re relying on the camera to do the heavy lifting of correcting lens anomalies or in software, but when the timing is right, this lens can produce nice contrasty images, which can be very pleasing.

How Does It Compare?

When it comes to wide-angle zooms, one other option could be the Panasonic 12-35mm f/2.8. The Olympus has the edge in that it goes slightly more telephoto, with an arguably more consistent operation in sharpness and detail across the range. The Olympus is slightly better when completely wide open, but the Panasonic has the edge at the most zoomed in range.

There’s also the consideration of stabilization. Strapped onto a Panasonic body, you already have in-body OIS, which is not available on the Olympus, but the Olympus M.Zuiko 12-40mm f/2.8 PRO is also slightly cheaper. Both of these lenses are good contenders, so it could be on both of these points that are the deciding factors.

Olympus M.Zuiko 12-40mm f/2.8 PROPanasonic 12-35mm f/2.8
Elements14 elements/9 groups14 elements/9 groups
Weight 382g305g


The Olympus is definitely the better choice if you’re shooting mostly wide-angle, but in reality, its if the focal lengths cover the most useful bases. So, it’s if this lens is the most general all-rounder than anything else. In this regard, the Olympus M.Zuiko 12-40mm f/2.8 PRO does a very good job of covering the most useful focal lengths.

The focus ring operation may take a lot of time to get used to, but overall a very recommended lens.

The Review

Olympus M.Zuiko 12-40mm f/2.8 PRO

The Olympus M.Zuiko 12-40mm f/2.8 PRO is a high-quality, wide-angle zoom, which in reality can cover most useful focal lengths. It does suffer from some edge softness and vignetting, but overall a very capable lens.


  • Sharp when wide open
  • Weather proofing
  • Price


  • Focus ring
  • Diffraction after f/8

Olympus M.Zuiko 12-40mm f/2.8 PRO DEALS

Review Breakdown






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