Update January 2026. It’s hard to believe just how long ago it was since I wrote this review. I stand by the fact that the Olympus 12-40mm f/2.8 Pro is still a fantastic lens and one that I used for years. I am heading back to the UK next week, where I will pick up my OM1 Mark II and the OM System 12-40mm f/2.8 Pro mark II. Essentially the same lens. That says a lot about how I regard this lens. I still use the newer version, to this day, 8 years later. In fact I’ve just featured it in my best lenses for travel photography with the Om-3 article. Stay tuned for more OM Systems articles coming soon. You can see my OM1 review here and why I bought the OM-3 here.

In this Olympus 12-40mm f2.8 review I will go through the pros and cons of this professional grade zoom lens after having used it for well over a year in my personal and professional work.

The Olympus 12-40mm f/2.8 was the first in Olympus’ Pro series of lenses designed for Micro 4/3 cameras. It is a weatherproof (dust, splash and freeze proof) fixed aperture zoom lens offering the 35mm equivalent field of view of a 24-80mm lens. It has a fixed aperture of f/2.8 throughout the zoom range with a filter thread of 62mm.

Build Quality

The first thing you will notice when you pick up the 12-40mm is the build quality. Like all of the Olympus Pro range of lenses it is extremely well made. At 382 grams and featuring a metal construction it feels solid in the hand and inspires confidence in use. For me it fits perfectly on the Olympus E-M5 II with the HLD-8G grip attached or on the EM1 and Em1 II giving you a weather sealed combination.

There is also an additional function button on the lens which you can program to activate a variety of features by simply customising it in camera.

While it is a larger lens for Micro 4/3 in comparison to some of the tiny primes, it is not oversized and much smaller than something like the Canon 24-70mm f/2.8. You can carry it attached to your camera all day and not notice the weight.

Olympus 12-40mm f2.8 Review – Focus

This is going to be a very quick section because all there is to say is that focus is as fast as any lens on the system. It is instantaneous to focus and is deadly accurate. Absolutely no issues here.

The zoom ring is nicely damped and it features a manual focus clutch mechanism that allows you to easily swap between auto and manual focus simply by pulling the clutch back or pushing it forward. It uses focus by wire but don’t let that put you off as the focus ring is incredibly smooth and allows you to easily and finely adjust your focus.

Zoom markings are shown for 12, 14, 18, 25, 35, and 40mm. If you pull back on the focus ring you put the lens into manual focus mode and reveal a focus scale. The focus scale has markings at 1’, 2’, 5’, and .2m, .5m, and 1m, plus infinity. Close focus is 8” (0.2m), and the lens can produce a 1:3.3 magnification ratio at 40mm.

The Olympus 12-40mm zooms externally so it increases in length from 3.3″ -5″ when extended.

Olympus 12-40mm f2.8 Review – Image Quality

The 12-40mm pro does suffer with some barrel distortion at the wide end if you shoot raw. The Jpegs are corrected in camera and the software does a good job in most cases. At 40mm there is a slight amount of pin cushion distortion. If you are shooting raw and have straight lines in your shots then you will need to correct in post.

The lens also shows some vignetting when wide open at f/2.8. This is easily corrected in post. I guess Olympus tried to keep this constant f/2.8 zoom as small as possible and that means the image circle only just covers the micro 4/3 sensor.

This lens handles chromatic aberration very well and I see very little sign of fringing even when shooting high contrast scenes. It also handles flare well.

The Olympus 12-40mm is sharp from 12mm all the way through to 40mm even wide open at f/2.8. At 12mm the corner performance is slightly softer than the centre but still way better than something like a Canon 17-40mm L. As mentioned the lens is bitingly sharp in the centre at f/2.8 and performance increases slightly when stopped down to f/4.

While f/2.8 on the Micro 4/3 format does not offer the same shallow depth of field as on 35mm sensors it is still capable of allowing your subject to be isolated from the background as shown in the above portrait. The bokeh from the Olympus 12-40mm f/2.8 at 40mm is enough for portrait work and the rendering is smooth and not overly busy. While it couldn’t be described as creamy it is not nervous and distracting and so works well. If you want a dedicated portrait lens then I suggest that you check out my Olympus 75mm f1.8 review or 45mm 1.8 review

Conclusion

Overall I would rate the Olympus 12-40mm f2.8 as one of the best zooms I have used. It is very well-built and combined with my EM5II or an EM1 series body offers excellent weather-sealing and a very useful focal range.

In terms of image quality sharpness is outstanding throughout the zoom range enabling you to shoot it wide open at f/2.8 without concern. It can do everything from wide-angle landscapes to portraits and it does it all well. Yes other lenses may be better at specific roles but none offer the versatility and fixed bright aperture of this lens.

If you are trying to decide between this lens and the Panasonic 12-35mm (mark i or mark II) then it really comes down to a few factors as optically they are very similar. The Olympus is better at the wide end and offers a little more range at the long end. However the Panasonic is slightly sharper at 35m than the Olympus is at 40mm.

If you are shooting on a Panasonic body then perhaps you might prefer to go with the Panasonic lens to take advantage of Panasonic’s depth from defocus system and in the case of the mark ii lens their dual sync IS. The Panasonic lenses are both lighter than the Olympus.

However having owned all 3 lenses and as an owner of the Panasonic GH5 and Olympus EM5 II I decided that the build quality of the Olympus 12-40mm edged out the Panasonic and so I kept it over its rivals. When I say edged out, it is night and day. The Panasonic’s feel like a consumer grade lens with very good optics. The Olympus 12-40mm feels like a professional grade lens in every way.

During my testing, dual sync IS between the GH5 and 12-35mm ii made no noticeable improvement in the image stabilisation and didn’t allow me to handhold shots for any longer than when using the Olympus 12-40mm f/2.8 on the GH5.

If you are going to own just one lens for Micro 4/3 then this may very well be the best choice. Make sure to check out my Olympus 25mm 1.2 Pro review as well.