A Micro Four Thirds Standard Zoom Lens Review. I take a look at the features and sharpness as well as distortion and vignetting. The four tested lenses are the Olympus M.ZUIKO DIGITAL ED 12-50 mm 1:3.5-6.3 EZ, the Olympus M.ZUIKO DIGITAL 14-42 mm 1:3.5-5.6 (I), the Panasonic LUMIX G VARIO 14-42mm F3.5-5.6 ASPH. MEGA O.I.S. (I) and the Panasonic LUMIX G VARIO 14-45mm F3.5-5.6 ASPH. MEGA O.I.S.

Hier klicken für die deutsche Version des Artikels.

Features

The Olympus M.Zuiko 12-50mm offers the most feature wise: It is the only non-pro Micro Four Thirds lens that is weather sealed and it has an internal electronic zoom. Further it offers an additional “L-FN” button and a macro mode with roughly a 1:3 reproduction scale. It is also the only of the four tested lenses, which offers 12mm at the wide end.
Both Panasonic lenses feature an optical image stabilization. How useful this is depends on your camera, if it offers in-body stabilization that is compatible with stills and video, the O.I.S. is pretty useless, if your camera has no stabilization it is a must-have for many people. The only difference in features between the two lenses from Panasonic is the physical O.I.S. switch on the 14-45mm. On the 14-42mm you have to turn stabilization on and off in the camera menu.
Least to offer has the Olympus M.Zuiko 14-42mm (I): It is the most compact of the lenses, but its noisy AF-drive and its rotating front element are not state-of-the-art anymore, as the first is bothersome for video recording and the second makes it nearly impossible to use circular polarization filters.

Sharpness of the Micro Four Thirds Standard Zoom Lenses

As there are forty comparison images, I posted them in three sub articles:
Sharpness at 14mm
Sharpness at 25mm
Sharpness at 42mm

The video version of „Micro Four Thirds Standard Zoom Lens Review“ on youtube also includes all comparison pictures: http://youtu.be/TGmNJo8_gSk

Please note: Different copies of the same model can vary in quality. It is possible that I have an extremely good copy of one lens and a very bad copy of another, but this is a limitation that even professional reviews suffer from.

14mm

At maximum aperture, it is hard to declare a winner for the image center. The Olympus M.Zuiko 12-50mm and the Panasonic Lumix 14-45mm are both good. The Panasonic Lumix 14-42mm (I) is noticeably worse and the Olympus M.Zuiko 14-42mm (I) is the worst.
This changes somewhat at the image borders: The Panasonic 14-45mm is the best, while the Panasonic 14-42mm and the Olympus 14-42mm share the second place, the M.Zuiko 12-50mm is clearly the worst
Stepped down to F/5.6 all four lenses have good sharpness in the image center, only the Lumix 14-45mm is marginally sharper than the other three. At the image border there are more differences. Again, the Panasonic 14-45mm is the best and the Olympus 12-50mm is the worst of the four lenses. The M.Zuiko 14-42 (I) and the Lumix 14-42 (I) are very similar, perhaps the Olympus lens is a little bit better.

Overall, the best lens at 14mm is the Panasonic 14-45mm. The Panasonic 14-42mm (I) and the Olympus 14-42mm (I) share the second place. The least sharp of the lenses is the Olympus 12-50mm, which is especially disappointing as it is the only of the four lenses that starts at 12mm.

25mm

The sharpest lens in the image center at maximum aperture is the Olympus M.Zuiko 12-50mm. Astonishingly the Pansonic Lumix 14-45mm is the least sharp of the four lenses. The Panasonic Lumix 14-42mm (I) and the Olympus 14-42mm (I) once again share the second place. The result for the image border again differs greatly. For the first time the Olympus 14-42mm (I) is the sharpest of the four lenses. The Panasonic 14-45mm is on the second place closely followed by the Olympus 12-50mm. The least sharp of the four is the Panasonic 14-42mm (I).
Stepped down to F/5.6 the M.Zuiko 12-50mm and the Lumix 14-42mm (I) share the first place for the image center. The Lumix 14-45mm is distinctively less sharp and the M.Zuiko 14-42mm captures even less details. At the image border all four lenses are very close, the Panasonic 14-45mm is maybe a bit better than the others and the Olympus 14-42mm (I) slightly worse.

At the normal focal length of 25mm it is hard to make out a clear winner. At maximum aperture the Olympus lenses are better than the ones from Panasonic. At F/5.6 the Olympus M.Zuiko 12-50mm and the Panasonic 14-42mm (I) share the first place and the Olympus M.Zuiko 14-42mm (I) is the least sharp of the four.

42mm

At 42mm I tested only one aperture as the maximum aperture is already F/5.6 (F/5.8 in case of the M.Zuiko 12-50mm). In the image center as well as the borders the Olympus M.Zuiko 12-50mm is the frontrunner closely followed by the Panasonic Lumix 14-42mm (I). At the image center the Olympus M.Zuiko 14-42mm (I) is noticeably worse and the Panasonic Lumix 14-45mm is the least sharp. In the borders it is vice versa, the Lumix 14-45mm is on the third place and M.Zuiko 14-42mm (I) is the least sharp.

The clear winner at 42mm is the Olympus M.Zuiko 12-50mm. The Panasonic Lumix 14-42mm (I) is also good, while the Panasonic Lumix 14-45mm and the Olympus 14-42mm (I) disappoint.

This spreadsheet shows the results. “1.” means first place, “4.” last place.

Transmission

All four lenses start with a maximum aperture of F/3.5, but at 25mm there are huge differences. The Olympus M.Zuiko 14-42mm (I) is the fastest of the lenses with a maximum aperture of F/4.4, closely followed by the Panasonic lenses with F/4.6 (14-42mm) and F/4.8 (14-45mm). The Olympus M.Zuiko 12-50mm is the slowest of the lenses with a maximum aperture of F/5.1. At 42mm all lenses have a maximum aperture of F/5.6, except the M.Zuiko 12-50mm which is marginally slower (F/5.8).

Distortion and Vignetting

I made no special tests regarding distortion and vignetting, but I took a close look at the test pictures for sharpness. Keep in mind, that these are uncorrected raw files, jpgs are corrected by the camera and show different results.
All four lenses show a great amount light falloff at 14mm, at maximum aperture as well as stepped down to F/5.6. In this regard the Panasonic lenses are even worse than the Olympus lenses. At 25mm and 42mm vignetting is not an issue.
Lets have a look at the distortion: The least distorted at 14mm is the Olypus M.Zuiko 12-50mm, closely followed by the Olympus M.Zuiko 14-42mm (I), again the Panasonic lenses are clearly worse, with the 14-45mm being a bit better than its successor. At 25mm The M.Zuiko 12-50mm and the Lumix 14-42mm (I) show no distortion and on the other two is it barely noticeable. At 42mm it is also not an issue, the Panasonic lenses show no distortion and you will not notice it on the Olympus lenses.

Micro Four Thirds Standard Zoom Lens Review Conclusion

The Micro Four Thirds Standard Zoom lens review has a clear winner, the Olympus M.ZUIKO DIGITAL ED 12-50 mm 1:3.5-6.3 EZ. It offers the best features, an ultra-wide angle and is overall the sharpest of the lenses. But it is not flawless, especially the low sharpness at the image borders in wide angle pictures is a great disappointment. Let us hope Olympus will update the lens to a better version II.
The result of the Panasonic lenses is a surprise. Generally the Panasonic LUMIX G VARIO 14-45mm F3.5-5.6 ASPH. MEGA O.I.S. is considered to be much better than its successor, the Panasonic LUMIX G VARIO 14-42mm F3.5-5.6 ASPH. MEGA O.I.S. (I), but my test did not verify this prejudice. Overall the two lenses are very similar.
The worst of the four lenses in the Micro Four Thirds Standard Zoom lens review is the Olympus M.ZUIKO DIGITAL 14-42 mm 1:3.5-5.6 (I). It is no wonder Olympus replaced it with an updated version years ago.

P.S. I have bought the updated version of the Olympus M.Zuiko 14-42mm and the Panasonic Lumix 14-42mm and will review them as soon as I have the time.