Panasonic 14mm f/2.5 ASPH LUMIX G

SLRgear Review
January 29, 2011
by Andrew Alexander

Panasonic released its 14mm ƒ/2.5 pancake prime lens in the fall of 2010, going even wider than the previous 20mm ƒ/1.7 prime. On micro four-thirds camera bodies, the lens will produce an effective field of view of 28mm.

There is no hood made for this lens, which is available now for approximately $400, and can also be purchased with the Panasonic GF-2 as a kit.

Sharpness
The Panasonic 14mm ƒ/2.5G produces very sharp images. Used at its widest aperture of ƒ/2.5, the resulting image is sharp throughout the majority of the center of the image, moving only to slight softness in the very corners. Stopping down reduces the impact of corner softness; even by ƒ/2.8, corner softness becomes very slight. At ƒ/4 and smaller, the lens is practically tack-sharp across the frame until it starts to hit diffraction limiting at ƒ/11. Overall sharpness isn't really impacted until ƒ/16 however, where edge-to-edge sharpness is just slightly soft. Fully stopped-down at ƒ/22, the lens produces images that are somewhat soft, but not exceptionally so.

Chromatic Aberration
CA is somewhat high for this lens, and not just in the corners. The effect is somewhat constant - there's no aperture setting which will noticeably mitigate the results, which are really only apparent in areas of high contrast. The effect is more noticeable in the corners, as one might expect in a wide-angle lens, but can also be noted throughout the rest of the image as well.

Shading (''Vignetting'')
Corner shading is a small consideration for the Panasonic 14mm ƒ/2.5G, producing an image at ƒ/2.5 with corners that are up to 3/4 of a stop darker than the center. Light falloff is reduced as the lens is stopped down, until it reaches its lowest level of 1/3 EV at ƒ/8.

Distortion
The lens produces a light amount of barrel distortion, though it should be noted that Panasonic and other micro four-thirds camera bodies do incorporate some automatic correction for distortion. In the corners the barrel distortion is relatively small, at just +0.5%.

Autofocus Operation
Mounted on our Olympus E-P1 test body, the Panasonic 14mm ƒ/2.5G took less than a second to slew through its entire range of focus. It is very fast as there is little to move inside the lens when focusing. Small changes are extremely fast. We also tried the lens on the Panasonic GF2: the lens is slightly faster to focus on the GF2 due to the way the E-P1 does its focusing. The front element does not rotate during autofocus operations.

Macro
Look elsewhere for macro: the lens produces just 0.10x magnification, and has a minimum close-focusing distance of just over six inches.

Build Quality and Handling
The 14mm ƒ/2.5G is a nice looking, very compact, pancake style lens that looks great on the Panasonic GF2 body. The lens is very lightweight at just 55 grams (just under 2 ounces). The lens features 6 elements in 5 groups, and seven circular diaphragm blades make up the aperture. As our technician Rob puts it, ''It weighs next to nothing and is about the size of three Oreo cookies stacked on top of each other. It could be carried in a shirt pocket if needed.''

There is only one ring on the lens and that is for manual focus. There are no buttons on this lens, and there is no depth of field scale either - there simply isn't any room for it. The lens is made of black polycarbonate to keep the weight down, and is made in Japan. The 46mm filter threads are plastic, and the body mount is metal. The lens balances nicely on the GF2 or E-P1 camera bodies.

The only control surface on the lens, the manual focusing ring, has a plastic ribbed texture and is a scant 1/4'' wide. The ring will turn forever in either direction, not being limited at the infinity or close-focusing distances. The front element does not turn during auto or manual focus.

As previously mentioned, no hood is available for this lens.

Alternatives

Panasonic 20mm ƒ/1.7 ASPH LUMIX G ~$400
The Panasonic 14mm is technically sharper than its 20mm, though the numbers are so slightly difference you may not even notice it in practice. The real advantage of the 14mm in this case is it is substantially wider - 75 degrees instead of 57. Otherwise, the 20mm ƒ/1.7 offers just over a full stop of extra light-gathering ability, better CA tolerance and much less distortion.

Olympus 17mm ƒ/2.8 M.Zuiko Digital ~$300
The Panasonic 14mm is sharper than the Olympus 17mm, and offers a wider field of view as well. Both lenses have their issues with CA, corner shading isn't much better on the Olympus, and both distort about the same.

Panasonic 14-45mm ƒ/3.5-5.6 ASPH MEGA O.I.S. LUMIX G VARIO ~$310
Panasonic's zoom kit lens may not offer as wide an aperture as the 14mm ƒ/2.5G, but it's almost as sharp, offers better results for CA, and slightly less distortion, as well as a telephoto option (it zooms out to 45mm) and image stabilization. Coupled with a lower price tag, the only thing the 14mm ƒ/2.5G has over it is its size and weight: the 14-45mm is substantially larger, and weighs more than three times as much, at 195g.

Conclusion
With sharp results and only slight issues with CA, Panasonic has produced a very nice walk-around lens with the 14mm ƒ/2.5G.

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.