Olympus 14-150mm f/4-5.6 ED M.Zuiko Digital

SLRgear Review
June 11, 2010
by Andrew Alexander

Announced in November 2009, the Olympus 14-150mm ƒ/4-5.6 ED M.Zuiko Digital is the all-in-one ''vacation lens'' for the PEN digital camera. Because of the small size of the four-thirds camera sensor, the lens has an effective field of view of 28-300mm.

The lens is designed specifically for the micro-four-thirds camera format. It isn't a "constant" lens, in that as you increase the focal length, the maximum aperture size decreases, though the minimum remains at ƒ/22. The following table reflects the changes:

These figures just correspond to the focal lengths marked on the lens; in actual usage, the widest aperture adjusts quite precisely in conjunction with the focal length setting. As you zoom in and out at the widest aperture, you can see the aperture changing in one-tenth increments.

A lens hood is available separately, the LH-61C Lens Hood. The lens takes 58mm filters and will be available shortly for around $700.

Sharpness
Generally, sharp images with this lens are best achieved with the lens in the middle of the zoom range (~50mm). Stopping down to ƒ/8 provides optimal sharpness.

Shot wide open at wide angle (ƒ/4 at 14mm), the lens shows good results for sharpness, with a good sweet spot in the middle of the frame (~1.5 blur units) falling off to slight corner softness (~2 blur units). Stopping down provides only a marginal gain in sharpness at this focal length at ƒ/5.6, and by ƒ/8 diffraction limiting sets in. By ƒ/11 the corners are creeping up to 3 blur units and the central sweet spot of sharpness is only a small point; by ƒ/16, sharpness is average (~2 blur units in the center, 4 in the corners), and by ƒ/22 the corners are reaching 6 blur units.

In the mid range, the image is appreciably sharper. By 45mm the largest aperture attainable is ƒ/5.4, so while you won't be blurring out backgrounds with this aperture, it does improve sharpness. At these settings, sharpness is quite good, around 1.5 blur units across the frame, and stopping down improves it further: at ƒ/8, the image is just over 1 blur unit across the frame. Stopping down further doesn't produce further sharpness, but it doesn't show quite the same degradation of performance we noted when used wide open. At ƒ/16 we see just under 2 blur units across the frame; at ƒ/22, it's just under 3 blur units.

Zoomed in, the lens shows its flaws to some degree. Our sample showed some slight de-centering at 70mm and greater; performance wide open at ƒ/5.6 is similar to wide-angle performance, a sweet spot of sharpness with corner softness. It's managed by stopping down; at 150mm and ƒ/11, there's a good spot of central sharpness in the range of 1.5 blur units, and corners in the 3-4 blur unit range. Stopping down further doesn't produce any further gains, and by ƒ/22 the lens produces images of around 4 blur units across the frame.

Chromatic Aberration
Chromatic aberration is quite strong in this lens, but in terms of at what settings you'll notice it, it's all over the map. It's fairly good at 14mm, becoming more noticeable when the lens is stopped down considerably. The best performance (ie., absence of CA) is found at 25mm. At 45mm and greater, CA is strongest with the aperture wide open, and reduces as the lens is stopped down. At 70mm and 100mm, CA is very strong in the corners wide open at ƒ/5.4.

Shading (''Vignetting'')
There's some corner shading when using the Olympus 14-150mm ƒ/4-5.6 M.Zuiko, but it's not excessive; mostly when using the lens at ƒ/8 or below. There isn't any shading to be found between 25 and 45mm, otherwise the most you'll see is a case where the corners are two-thirds of a stop darker than the center, at 14mm and ƒ/4.

Distortion
The E-P1 corrects distortion in-camera, so it's no surprise that there is very little distortion evident in our test images. There is a fraction of pincushion distortion at 14mm, but otherwise, it's essentially zero.

Autofocus Operation
The Olympus 14-150mm ƒ/4-5.6 M.Zuiko autofocuses quickly, going from closest focus to infinity in less than one second. It is virtually silent in its operation, as there is (according to the Olympus press release) only one lens element which moves to focus. Point-to-point focusing is very quick. The front element does not rotate during focus operations.

Macro
The lens provides average macro performance, which isn't surprising as it's not marked specifically as a macro lens. Its minimum close focusing distance is around nineteen inches, and it provides 0.24x magnification.

Build Quality and Handling
As all M.Zuiko micro-four-thirds lenses, the Olympus 14-150mm ƒ/4-5.6 is very small, at just around 3 1/4 inches long. The lens doesn't weigh much either, at 10 oz (290 grams). It uses plastic construction to achieve this weight savings, its exterior a matte black finish. The lens mount is metal, and the 58mm filter threads are plastic. The lens does not have a distance scale or depth of field markings, nor does it have any control switches of any kind.

The zoom ring of the lens is plastic with large raised ribs, about an inch wide. The ring takes about 80 degrees to move through its range of focal lengths and turning action is very smooth - firm but not too tight, requiring two fingers to move. There is significant extension with this lens - when zoomed in to 150mm, the lens grows in length by 2 1/2 inches. Given its small size, zoom creep isn't a factor.

The focus ring of the lens is an indented ribbed plastic just 1/2 inch wide. The ring uses a ''fly-by-wire'' system to achieve manual focus results, and the E-P1 provides some interesting manual focus functionality. When you turn the focus ring with the MF assist option on, the camera brings up a magnified center view to allow you to precisely focus. The ring will turn forever, as there are no hard or soft stops in the focus ring, and there's no way to know how many ''degrees'' of turning action are available. The fly-by-wire operation does allow for an interesting option: you can set the focus ring direction to either left or right, from the camera's menu.

At the time of writing it's not clear whether or not the 14-150mm ƒ/4-5.6 M.Zuiko ships with its LH-61C lens hood; we didn't get one with the sample we tested. The lens is a petal-shaped hood, which attaches via a bayonet mount.

Alternatives

There's precious little at this stage in terms of alternatives; just the Panasonic 14-140mm. Normally we'd look at options from Sigma, but while there are some lenses available for the four-thirds mount, none of them cover the same zoom range as the 14-150mm.

Panasonic 14-140mm ƒ/4-5.8 ASPH MEGA O.I.S. LUMIX G VARIO HD ~$800
The Panasonic lens is sharper wide open than the Olympus, and marginally better when stopped down; results for chromatic aberration are also much better, but it's not clear whether that's the lens performance or the camera removing CA in post. Distortion is also removed in the camera, so that's hard to compare as well. Mega OIS isn't necessary in the E-P1, as the camera has image stabilization built-in. Your mileage may vary.

Conclusion
For what it offers, the Olympus 14-150mm ƒ/4-5.6 is a very good lens, not the sharpest we've tested but certainly very good for a superzoom. It's marred by some high chromatic aberration at certain focal lengths, but for the wide range of focal lengths the lens offers, it's probably a small price to pay for the all-in-one versatility.

Sample Photos

The VFA target should give you a good idea of sharpness in the center and corners, as well as some idea of the extent of barrel or pincushion distortion and chromatic aberration, while the Still Life subject may help in judging contrast and color. We shoot both images using the default JPEG settings and manual white balance of our test bodies, so the images should be quite consistent from lens to lens.

Still Life shot

VFA target

As appropriate, we shoot these with both full-frame and sub-frame bodies, at a range of focal lengths, and at both maximum aperture and ƒ/8. For the ''VFA'' target (the viewfinder accuracy target from Imaging Resource), we also provide sample crops from the center and upper-left corner of each shot, so you can quickly get a sense of relative sharpness, without having to download and inspect the full-res images. To avoid space limitations with the layout of our review pages, indexes to the test shots launch in separate windows.