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Lens review

Olympus M.Zuiko ED 12-100 mm f/4 IS PRO

14 February 2017
Szymon Starczewski

8. Vignetting

First let’s check the vignetting performance for JPEG files – appropriate thumbnails are shown below.

E-M5 II, JPEG, 12 mm, f/4.0 E-M5 II, JPEG, 12 mm, f/5.6
Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting
E-M5 II, JPEG, 25 mm, f/4.0 E-M5 II, JPEG, 25 mm, f/5.6
Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting
E-M5 II, JPEG, 60 mm, f/4.0 E-M5 II, JPEG, 60 mm, f/5.6
Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting
E-M5 II, JPEG, 100 mm, f/4.0 E-M5 II, JPEG, 100 mm, f/5.6
Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting


The overall image is good because the vignetting level couldn’t be considered bothersome at any point. At a difficult combination of wide angle and the maximum relative aperture the light fall-off in the frame corners amounted to 26% (−0.88 EV). It is a value which might be noticeable but still you should consider it moderate. By f/5.6 it decreases to 20% (−0.66 EV), and by f/8 to 15% (−0.47 EV). Further stopping down doesn’t have any measurable influence on vignetting.

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At bigger focal lengths there are almost no problems, not even at the maximum relative aperture. At 25 mm you lose only 8% (−0.26 EV) of brightness and at 60 mm that value reaches 13% (−0.40 EV); on stopping down to f/5.6 it decreases once again to 8% (−0.24 EV).

The vignetting similar to the one visible at the wide angle appears also at the maximum focal length. By f/4.0 you get 24% (−0.80 EV), and by f/5.6 that value decreases to 11% (−0.32 EV).

RAW files are characterized by a higher vignetting level due to the fact that, when you pass to JPEG format, images are cropped and distortion corrected. Still, at bigger focal lengths the difference is cosmetic, never exceeding 2%. The shortest focal length is an exception to that rule – the distortion at that point was very high and the cropped area quite significant. As a result a RAW taken at 12 mm and by f/4.0 aperture loses as much as 41% (−1.54 EV) of light in frame corners.

What’s interesting, as you can notice below the results we got using the E-PL1are slightly higher than those coming from the E-M5 Mark II. Perhaps that discrepancy is due to slightly different sensors or a different layout of microlenses and/or light-sensitive cells.

E-PL1, RAW, 12 mm, f/4.0 E-M5 II, RAW, 12 mm, f/4.0
Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting
E-PL1, RAW, 12 mm, f/11.0 E-M5 II, RAW, 12 mm, f/11.0
Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting


In the E-M5 Mark II camera the image circle at 12 mm seems to cover the whole sensor but it is not true in the case of the E-PL1. On a significant stopping down of the aperture the very corners of the frame become completely black. It is an interesting result, showing that Micro 4/3 system sensors might differ from each other significantly. Still it’s nothing strange as the launches of the cameras used in our test are divided by 5 years.

Olympus E-M5 II, JPEG, 12 mm, f/4.0
Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting
Olympus E-M5 II, JPEG, 25 mm, f/4.0
Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting
Olympus E-M5 II, JPEG, 60 mm , f/4.0
Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting
Olympus M.Zuiko ED 12-100 mm f/4 IS PRO - Vignetting