Olympus 14-42mm f/3.5-5.6 ED M.Zuiko Digital

SLRgear Review
July 31, 2009
by Andrew Alexander

The kit lens for the new Olympus E-P1 micro four-thirds camera, the 14-42mm ƒ/3.5-5.6 M.Zuiko produces an effective field of view of 28-84mm when mounted on a compatible camera body. The micro four-thirds format will restrict compatible bodies to micro four-thirds mounts only; anything else would cause vignetting.

This lens isn't a ''constant'' lens, in that as you increase the focal length, the widest aperture gets smaller (higher ƒ-number). The following table reflects the changes:

The Olympus 14-42mm ƒ/3.5-5.6 zoom lens takes 40.5mm filters and is available as the kit lens with the E-P1 camera.

Sharpness
The 14-42mm ƒ/3.5-5.6 is a very sharp lens, even when used wide open at wide angle settings. It's slightly softer at its telephoto end, but when closed down a stop or so, all apertures are quite sharp.

When used wide open, the lens provided nicely sharp images, with just a little softening in the corners; all focal lengths were fairly sharp, with the exception of 42mm, where it softens noticeably wide open. Stopping down improves image sharpness, and indeed at 25mm the lens is tack-sharp at ƒ/5.6. At 42mm and ƒ/8, image sharpness improves a good bit, but stops short of the tack-sharpness of shorter focal lengths.

Above ƒ/8, diffraction limiting begins to affect the image sharpness, but only marginally - it's only by ƒ/11 - ƒ/16 that we note significant softening. The minimum aperture of ƒ/22 is best avoided, with very soft results at either wide angle (14mm) or telephoto (35-42mm). At 18mm or 25mm, image sharpness is surprisingly good for ƒ/22, though.

Overall, quite good performance used wide open, better stopped down slightly, and soft in the wide and tele ranges at ƒ/22.

Chromatic Aberration
At wide angle, maximum chromatic aberration is very high, increasing as the lens is stopped down. The huge spread between the maximum and average CA values reflects the fact that the worst CA is confined to the corners of the frame; the inner three-quarters of the frame isn't bad at all. Using the lens wide open at ƒ/3.5 is the best way to counter CA at wide angle, however even at this setting CA is still noticeable in areas of high contrast.

As the lens is zoomed towards the tele range, CA is vastly reduced, but is still slightly visible.

Shading (''Vignetting'')
Excellent results for corner shading - at every aperture and focal length setting, the corners are only a quarter-stop darker than the center, pretty much across the entire focal length and aperture range.

Distortion
There's a typical amount of wide-angle distortion when used at 14-18mm - +0.7% barrel distortion along the edges and in the corners - but it is uncomplicated distortion that would be easily fixable in post-processing. At 25mm the distortion evens out and is essentially non-existent from there all the way to 42mm.

Autofocus Operation
The lens took about a second to go from infinity to close-focus: quite fast, and nearly silent. Focus was quite confident, something we've been scrutinizing with Olympus' contrast autofocus detection method.

Macro
Macro performance is fairly good with the 14-42mm ƒ/3.5-5.6, at 0.24x magnification (1:4.2 reproduction), but it's no substitute for a dedicated macro lens.

Build Quality and Handling
The 14-42mm ƒ/3.5-5.6 is an all-plastic lens, quite small given the design parameters of the micro four-thirds system. The resulting package is quite small and light - the lens weighs just 150 grams (5.3 oz). The lens is available in either matte black or silver - the silver matching the finish of the E-P1. The plastic filter threads are a slightly less common size - 40.5mm - but this is in keeping with the miniscule profile of the lens. The lens mount is metal.

There's an Unlock switch on the lens whose purpose is unconventional compared to the usual lens lock, so as simple as it is, some explanation is required. The lens is stored in its retracted position, and the camera will not operate while the lens is retracted; an error message instead displays on the LCD. To deploy the lens, you turn the barrel to the left. Once you pass the 14mm mark, the lens Unlock switch clicks, effectively preventing the lens from accidentally retracting again when you move the zoom ring to the 14mm position. In a sense, this mechanism locks the lens into its open, usable position, and you must slide the Unlock switch forward to release the lens so that it can again retract for storage. This operation is unchanged from the predecessor lens. There is no distance scale on the 14-42mm II M.Zuiko, and neither is there a depth-of-field scale.

The zoom ring is a half-inch wide, plastic with alternating raised ribs sections that run lengthwise to the lens. The ring turns about 50 degrees through its range of focal lengths, and is quite easy to turn. There is some significant lens extension as the lens is zoomed out towards the tele end; specifically, the lens gets a half-inch longer at the widest angle setting (14mm) or the tele setting (42mm). At 25mm, it's at its shortest length.

The focus ring is located at the end of the lens, an indented plastic ring just 3/16'' wide. The ring is a fly-by-wire design, controlling focus electronically, so there are no hard stops at either the infinity or close-focus ends. It's not the most friendly of manual focus designs, but the 100% magnification on the LCD really helps nail an accurate focus. Given that focus is electronically controlled, you can assign the direction of focus to be either left or right.

Polarizer users should note that this lens rotates the front filter during autofocus. Our sample didn't ship with a lens hood, and it's not clear whether one is available or not.

Alternatives

Olympus 17mm ƒ/2.8 M.Zuiko Digital ~$300
At the time of writing, the 17mm prime is the only other micro four-thirds lens made by Olympus. The 17mm isn't as sharp at the 14-42mm zoom, but offers a faster ƒ/2.8 maximum aperture.

Panasonic 14-140mm ƒ/4-5.8 ASPH MEGA O.I.S. LUMIX G VARIO HD ~$850
Panasonic offers this lens for the micro four-thirds format, and it is indeed quite impressive. The lens isn't as sharp as the Olympus for the ranges they both cover, but the differential isn't very much - the big plus for the Panasonic is the vast zoom range that's available beyond 42mm. CA performance and distortion are both a bit better in the Panasonic than the Olympus, especially at the wide angle end.

Conclusion
Optically, the Olympus 14-42mm ƒ/3.5-5.6 tested quite well, showing good sharpness wide open, and even better when stopped down slightly. CA is higher than we'd like at wide-angle (especially in the corners, where it's pretty extreme), but happily the worst of it manifests only when the lens is significantly stopped down and in the corners at maximum wide angle. At 25mm, the lens offers excellent performance, tack-sharp at f/5.6. Results for Distortion and Corner shading were both excellent.

As kit lenses go, the 14-42mm is quite nice, and its compact design is quite welcome when handling the E-P1. We're not crazy about the somewhat loose feel to the front element, but that doesn't seem to affect optical performance.

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.