Panasonic GF5 Optics

Zoom Lens
A typical zoom ratio for a kit lens, with slightly better than average performance.

The above shots were taken with the Lumix G X VARIO PZ 14-42mm f/3.5-5.6 Power O.I.S. zoom kit lens. The 35mm equivalent focal length is about 28-82mm, a result of the GF5's 2x "crop factor." Results at full wide-angle are pretty good at f/8, but detail is just a touch soft across most of the frame, with hints of flare around bright objects. Extreme corners exhibit mild to moderate blurring and minor coma distortion. Chromatic aberration is well controlled at all focal lengths (the GF5 suppresses C.A.). Performance at medium focal length is also good, but again with a hint of softness and flare. At full telephoto, the lens is a little softer across the frame, and there is some noticeable vignetting (shading) in the corners. The GF5's digital zoom mode shows a typical loss of fine detail for such a high magnification.

Macro
A larger than average minimum area, with somewhat soft detail and strong corner shading. Flash throttled down well, though.

The Panasonic Lumix DMC-GF5's macro performance will depend entirely on the lens in use. However, with the 14-42mm X kit lens, the Panasonic GF5 captures a much larger than average minimum area measuring 3.72 x 2.79 inches (95 x 71 millimeters). Detail is good but a little soft across the frame at f/8, with additional softening in the corners. (Most lenses have some additional softening in the corners at macro distances.) There's also some fairly strong vignetting or corner shading in the extreme corners, much more than we're used to seeing especially stopped-down to f/8. The popup flash had no trouble throttling down at this distance, resulting in a pretty good exposure, though corner shading is still visible as expected (caused by the lens).

Geometric Distortion
Low geometric distortion with the 14-42mm X kit lens in JPEGs, though strong distortion in uncorrected raw files.

When shooting JPEGs, the Panasonic GF5's 14-42mm kit lens produces about 0.4 percent barrel distortion at wide-angle, which is much less than average and just slightly noticeable in its images. Pincushion distortion at full telephoto is just 0.1 percent, also lower-than-average and hardly noticeable. This is the tendency for the lens to bend straight lines outward (like a barrel -- usually at wide-angle).

To see how much correction is taking place in the camera, we converted raw files from the above shots with dcraw, which does not correct for distortion. As can be seen above, actual barrel distortion at wide-angle is very high at about 2.1%, while pincushion at telephoto is fairly high, at about 0.8%. We expect this for smaller interchangeable lenses though, so it's nothing to be concerned about unless you are using a raw converter which does not understand the embedded "opcodes" to perform distortion corrections automatically. Most raw converters these days (including Adobe Camera Raw and SilkyPix) are capable of applying distortion correction automatically, as specified by the manufacturer. There is however going to be some loss of resolution in the corners as a result of such correction, because pixels in the corners of the frame are being "stretched" to correct for the distortion. Obviously, a lens that doesn't require such correction, and is also sharp in the corners to begin with would be preferable, but relaxing constraints on distortion brings other benefits in the lens design, such as a very compact design.

Chromatic Aberration and Corner Sharpness
Low to moderate levels of chromatic aberration from the kit lens in JPEGs. Uncorrected raw files show higher amounts. Corners are somewhat soft wide-open, but improve when the lens is stopped-down.

Chromatic Aberration. Chromatic aberration in the corners of JPEGs taken with the Panasonic GF5's 14-42mm X kit lens is moderate at wide-angle, somewhat exacerbated by the blurring, but coloration is fairly dull and bluish. At full telephoto, C.A. is quite low in the corners. As usual, color fringing gradually reduces in brightness and width as it approaches the center of the image, where it is almost non-existent at both ends of the zoom range. Thus, the camera's processor does a pretty good job of reducing lateral C.A. in JPEGs (see below for uncorrected raw).

Corner Softness. The Panasonic GF5's 14-42mm X kit lens produces moderate blurring in all four corners at wide-angle when wide-open at f/3.5, with top corners a bit softer than bottom. The center is fairly sharp. Corners are also moderately soft at full telephoto, and the center is a bit soft as well.  

Vignetting. Some moderate corner shading ("vignetting") is noticeable from the difference in brightness of the center versus corner crops above. The GF5 does offer shading compensation (default is off), however the lab did not test that feature.

Stopped down to f/8, corner sharpness improves, but are still a touch soft. Center sharpness also improves slightly. Vignetting (corner shading) improves quite a bit to the point of being negligible.

Chromatic Aberration Suppression. As mentioned above, the Panasonic GF5 suppresses chromatic aberration in its JPEGs, with uncorrected raw files showing more distinct green and magenta coloration. Raw files converted with the bundled SilkyPix software or Adobe Camera Raw are automatically corrected for C.A. and geometric distortion, so we used dcraw for the uncorrected conversions above right.

Overall, not a bad performance for a kit lens. Sure, sharpness at telephoto could be better, macro could get closer, and there's noticeable vignetting in some situations, but we think those are worthwhile tradeoffs to most users for a zoom lens that's almost as compact as a pancake prime when stowed.

Accuracy
Excellent coverage accuracy from the LCD monitor.

The Panasonic GF5's LCD monitor proved quite accurate in record mode, showing just a touch over 100% coverage with our low-distortion Olympus 50mm f/2 reference lens. Excellent results here.