Olympus M.Zuiko 12-40 mm PRO - Johnsson Photo

First of all I want to state that I do not take any scientific tests on sharpness or ISO comparisons with other cameras. I just evaluate the pure shooting experience by going out taking photos.

I love using prime lenses and the Micro-Four-Thirds format offers some very, very good ones, like the outstanding 75 mm f1.8, the 60 mm Macro f 2.8 or the small but superb 20 mm f1.7. But sometimes the comfort of using a zoom lens would be nice. Very often zoom lenses compromise image quality when compared to prime lenses, but reading early reviews of the new Olympus Pro zoom, which were outdoing each other with positive impressions, encouraged me to get this lens.

Besides my 9-18 mm M.Zuiko wide-angle lens (which I almost do not count as a zoom lens since I use it almost exclusively at 9 mm) this is my only zoom lens. Main reason, alongside the promised image quality, I bought this lens, is the complete weather-sealing. I have the 60 mm macro which is also weather-sealed but it is not your typical walk-around lens and I wanted to use my E-M1 in rougher conditions, so this lens is a great companion.

Build quality

After unboxing the 12-40 mm you realize this lens is fairly heavy and big for mFT, but being a constant f2.8 zoom lens, the dimensions and weight are more than acceptable. Even more so if you compare it to Nikon’s or Canon’s standard 24-70 f2.8 zooms, which are huge.

The zoom and focus rings have nice resistance to them, nevertheless being precise even for smallest adjustments. I love how this lens looks, feels and operates. Especially when mounted on a body like the E-M1, with the better grip it feels very balanced. The material of this lens is very high-class being a metal construction and the feeling is wonderful.

If there is one thing about the construction of this lens I do not like, it is that lens barrel is not completely retracted at 12 mm but at 15-18 mm. But we are talking about an extension of roughly 0.5 cm at 12 mm so this should not be a problem.

As Olympus did with the 12 mm and the recent 17 mm f1.8, they implemented the snap-back focus ring on this zoom as well, allowing switching the lens to manual focus, by snapping the focus ring back. Using this function, provides a defined start and end to the focusing ring, which results in a very tactile manual focusing option, even though the lens is focusing by wire. It is a great and handy feature, which is implemented very well. Another great thing the Olympus’ engineers did with this lens, is adding one extra function button, sum up to a total of six customizable function buttons when used with the E-M1.

As with almost all mFT lenses, autofocus of this lens mounted on the E-M1 is very fast and accurate. I have noticed that the AF motor is producing noise in operation. However the sound is barely noticeable when you are out shooting.

Image quality

As early reviewers stated, this lens produces image quality which is among the best for any standard zoom lens of any format and I have to admit this statement is true. The images are razor sharp with vibrant color reproduction and great micro-contrast, and best of all, even wide open at f2.8. This comes very handy when you use this lens in dim conditions and as much light as possible is needed. It is certainly not as fast as some mFT primes, but f2.8 is very respectable for a zoom. In addition to the great quality wide open, this lens performs very well at all focal lengths. Bokeh is also very pleasant so this lens is capable of taking some nice portraits.


With a minimum focus distance of 20 cm (7.87”) this lens comes in very handy as a macro alternative when your dedicated macro lens is left at home or changing is impossible. Magnification is not 1:1 as with the 60 mm f2.8 macro lens, but it is good enough for many situations, for me anyway. Especially the snap-back focus ring is very useful when using this lens for macro allowing for easy switches to manual focus to finde the closest focus distance.

I find myself using this lens very often for macro shots, when I do not want to change lenses and full magnification is not required, and with all images produced by this lens I am very happy with the results.


After using this lens for almost one month, I can say, this is a wonderful lens. It is beautifully built, with a solid feel making this lens the perfect companion for tough shooting conditions, producing outstanding image quality in addition. This lens does not render my prime lenses obsolete by any means, but I do not need to have a bad feeling leaving them at home from time to time, going out with just this one lens. Well done Olympus.


  • - very sharp for a zoom lens
  • - great build quality
  • - fast aperture
  • - fast autofocus
  • - nice micro-contrast and vibrance
  • - handy macro capability
  • - completely weathersealed
  • - lens hood and pounch included



  • - none really

Sample images

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