Review Olympus 12-100mm f/4
The Olympus M.Zuiko 12-100mm F4 is a professional compact all-around zoom for Micro Four Thirds. The range corresponds with a 24mm to 200mm on full-frame. Usually, these kinds of zooms are not of the best optical quality. Packing a large zoom range of nearly 10 times into a compact lens only works if you make compromises in the area of image quality, right? The Olympus 12-100mm is the exception to the rule.
All in one: Olympus M.Zuiko 12-100mm F4
For a Micro Four Thirds lens, the Olympus M.Zuiko 12-100mm F4 is rather large, with dimensions of 77x116mm and a weight of 560 grams. We are talking here, though, about a lens that, converted to 35-mm equivalent, includes all the fields of view from 24mm through 200mm. At one end, it is a reasonable wide-angle, and at the other end, a hefty telephoto. In between, we find other popular focal lengths like 28, 35, 50, 85, 100, 135, 150 and 180 mm. This is a whole pile of lenses in one. The 12-100mm can also serve as a semi-macro lens. For many photographers, the Olympus M.Zuiko 12-100mm F4 is pretty much all they need. If you look at it that way, the weight and dimensions are a considerable savings, and it is quite a feat by Olympus that they have gotten so much into such a compact lens.
BUILD AND auto focus
The 12-100mm is part of the M.Zuiko PRO series from Olympus. That means that the lens is completely sealed against dust and moisture. In addition, it is guaranteed to work in the freezing cold. Olympus’s reputation in this area is outstanding, and you can thus trust that the 12-100mm will have no difficulty working in rainstorms or a snowstorm. You also feel that quality when you hold the lens. The whole lens is free of play, and the zoom and focus rings have exactly the right amount of resistance. The focus ring has the ‘focus clutch’ function, which we also find on the 12-40mm f/2.8 from Olympus. By pulling the focus ring back a bit, you switch from auto focus to manual focus. The manual focus has two hard stops for infinity and close up. You can’t endlessly and needlessly keep turning the ring, and that’s good. The fixed brightness of f/4.0 is good for photographers who like manual exposure or who do a lot of filming. As far as filming is concerned, the 12-100mm also has very little trouble from focus breathing. That means that the subject shows little sign of becoming larger or smaller when changing focus. When photographing, those kinds of things seldom get noticed, but that kind of zoom effect can be a real pain if it happens during filming. The lens also has image stabilization that can also be turned off on the lens.
A big zoom range is fun, but it won’t do much for you if the image quality of the shots is not good. Olympus has pulled out all the stops for this lens to perform as well as possible. It has 17 lens elements in 11 groups and a whole series of special glass types. And you see all that effort in the performance. Those are very good. In the RAW files, the sharpness in the wide-angle setting, at 12mm, is already optimal in the center at full aperture. The corners are reasonable then, but those become better after stopping down one stop, and then they are good as well. At f/5.6 and f/8, the center sharpness is a bit lower than at f/4, but the shots are truly sharp from corner to corner. At 18mm and 25mm, the center sharpness at f/4 and f/5.6 is maximal. The corners are already good at full aperture, but they get a bit better at f/5.6. If you zoom in further, then the quality of the lens slowly decreases at full aperture. It does not make much difference, but those who want maximum quality at 100mm are best off stopping down one stop.
In jpeg, with all lens corrections active, we see about the same image, but the performance is more even. It actually matters very little in jpeg for the sharpness which aperture you choose. At f/4, the lens is a bit better at 12mm than it is at 100mm, but the difference is quite small.
This lens has strikingly little trouble with vignetting, which in comparison with full-frame lenses benefits the signal-to-noise ratio in the corners. At full aperture, there is still some vignetting visible, but even that disappears after stopping down one stop. We measured the distortion with and without corrections. Uncorrected, there is barrel-shaped distortion of 1.5% in the 12mm mode, which runs to a bit more than 0.6% pincushion shaped at 100mm. In the 25mm mode, the lens is practically free of distortion. Corrected, just under 0.5% barrel-shaped distortion left at 12mm and slight pincushion distortion of an average of around 0.2% across the rest of the range. In practice, that is negligible. With a maximum brightness of f/4, the 12-100mm is not a bokeh monster. But you can still get quite nice blurred backgrounds if you keep plenty of distance between your subject and your background in the 100mm mode. Any blurred light sources in the background are displayed quite beautifully. With less good lenses, the bokeh balls have hard edges and an onion-ring structure in the middle. With the 12-100mm, it looks great.
IMAGE STABILIZATION? Super!
The Olympus M.Zuiko 12-100mm F4 has image stabilization in the lens. Olympus cameras also have image stabilization, and in the most recent generations, 5-axis image stabilization. If you combine the 12-100mm with the new Olympus OM-D E-M1 Mark II, they collectively deliver an image stabilization benefit of 6.5 stops, according to Olympus. That could well be right. In the testing that we did, it appears that the Olympus M.Zuiko 12-100mm F4 on the OM-D E-M1 Mark II at 2/3 of a second with image stabilization achieves the same sharpness as the lens and the camera without stabilization at 1/50 of a second. That is more than five stops. Under the right conditions, a stabilization of 6.5 stops is quite possible. In practice, we were indeed able to take sharp pictures with exposure times of more than 1 second shooting by hand. That outstanding image stabilization means that with the 12-100mm, you can also photograph well in low light, despite the brightness of f/4. With the 12-100mm and the E-M1 Mark II, you can even photograph beautifully flowing water with long shutter times without a tripod. The image stabilization also makes beautiful video recordings by hand possible without vibrations or jumps. For videographers who like to work without being too intrusive, do not have a gimbal or GlideCam, or who do not have time to work with those kinds of tools, the combination of a E-M1 Mark II and this 12-100mm is a solution. Thanks to the good stabilization, you can film with this set while walking, panning or even simulate slider shots.
Olympus M.Zuiko 12-100mm F4 can also focus pretty close up. The 12-100mm manages a magnification of 0.3x. Converted to 35-mm equivalent, that is an enlargement of 0.6x. The minimum image field that you can get in frame with the Olympus M.Zuiko 12-100mm F4 is thus some 57x43mm. With the 12-100mm, you can also make reasonable macro photos. It’s nice that the distance between the front of the lens and the subject, thanks to the longer focal length, still pretty significant. Insects or other smaller animals will not be chased off so quickly.
ConclusiON REVIEW Olympus 12-100mm f/4 PRO
WYSIWYG score: This table shows the performance of this lens if you save the files in the camera as jpg, where you have applied all available in-camera lens corrections. This score gives you for this lens/test camera combination: "What you see is what you get".
Pure RAW score: This table shows the performance of this lens if the file is stored in the camera in RAW format. This score approaches the intrinsic quality of the combination of lens and test camera. If you use lens correction profiles in Photoshop or Lightroom to convert RAW files, then the RAW scores for distortion, vignetting and chromatic aberration are even better.