Panasonic G85 Optics

12-60mm Zoom Lens
A higher-than-average 5x zoom ratio for a kit lens, with decent performance.

The Panasonic G85's 12-60mm f/3.5-5.6 kit lens has a 35mm-equivalent focal length of about 24-120mm, a result of the G85's 2x "crop factor." That's both wider and longer than most kit lenses.

Performance at full wide angle was pretty good at f/8, with good sharpness and contrast across most of the frame, though there are hints of flare around bright objects. Extreme corners exhibit mild blurring and minor coma distortion, though this scene isn't great for judging corner performance (see below for lab results). Chromatic aberration is well-controlled, because the G85 suppresses it. Performance at medium focal length (50mm eq.) was very good, with excellent sharpness and contrast across the frame. At full telephoto and f/8 performance was quite good, with very good sharpness and contrast across most of the frame.

The G85's 2x digital zoom worked well, but 4x shows a lot of chroma noise and some interpolation artifacts, so digital magnification that high should be avoided except for very small prints.

Macro
A slightly larger than average minimum area, with good detail. Flash throttled down well.

The Panasonic Lumix G85's macro performance will depend entirely on the lens in use. However, with the 12-60mm kit lens, the Panasonic G85 captured a slightly larger than average minimum area measuring 2.40 x 1.80 inches (61 x 46 millimeters). Sharpness is very good across much of the frame at f/8, though corners are a little soft. (Most lenses have some additional softening in the corners at macro distances.) The popup flash throttled down well at this distance, resulting in a very good exposure.

Geometric Distortion
Moderate geometric distortion with the 12-60mm kit lens in JPEGs at wide angle, though strong distortion at wide angle in uncorrected RAW files.

In camera JPEGs, the Panasonic G85's 12-60mm kit lens produced about 0.6 percent barrel distortion at wide angle, which is moderate and noticeable in images. Pincushion distortion at full telephoto was less than 0.1 percent, and barely visible. 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 matching RAW files from the same test shots with dcraw, which does not correct for distortion. As can be seen above, the actual barrel distortion at wide angle was quite high at about 2.2%, while pincushion at telephoto was about 0.4%. We expect this for modern interchangeable lenses though, so it's nothing to be too concerned about unless you are using a RAW converter which does not understand the embedded lens profile to perform distortion corrections automatically. Most RAW converters these days (including Adobe Camera Raw and the bundled SilkyPix software) 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 more compact design.

Chromatic Aberration and Corner Sharpness
Low levels of chromatic aberration from the kit lens in JPEGs. Uncorrected RAW files show higher amounts. Some soft corners even stopped down to f/8.

Chromatic Aberration. Chromatic aberration in the corners of in-camera JPEGs taken with the Panasonic G85's 12-60mm kit lens was moderate at maximum wide angle with some noticeable blue fringing, but fairly low at full telephoto with some minor reddish fringing. The camera's processor did a pretty good job of reducing CA in JPEGs (see below for uncorrected RAW).

Corner Softness. The Panasonic G85's 12-60mm kit lens produced somewhat soft corners with reduced contrast in all four corners wide-open at f/3.5, though softness didn't extend very far into the frame. The center was quite sharp. At full telephoto, corners were also a bit soft with lower contrast, while the center showed good sharpness and contrast.

Vignetting. Some moderate corner shading ("vignetting") occurred at wide angle while fairly mild shading was visible at full telephoto, as can be seen from the difference in brightness of the center versus corner crops above.

F/8: Stopped down to f/8, corner sharpness improved significantly at wide angle, though corners were still not as sharp as the center (much of the softness is likely due to the strong distortion correction), and corners still showed some chromatic aberration though it has been reduced. Sharpness in the center was still quite good, though not quite as sharp as wide open due to diffraction. At full telephoto, contrast and sharpness in the corners only improved very slightly, while the center also lost a touch of softness due to diffraction. Vignetting (corner shading) improved quite a bit, but was still somewhat noticeable at wide angle.

Chromatic Aberration Suppression. As mentioned above, the Panasonic G85 applies lateral chromatic aberration correction to its JPEGs, as uncorrected RAW files showed fairly bright blue/green coloration at wide angle but only mild magenta/red fringing at telephoto. RAW files converted with the bundled SilkyPix software or Adobe Camera Raw are automatically corrected for lateral chromatic aberration and geometric distortion, so we used dcraw for the uncorrected conversions above right.

Shading Compensation
The Panasonic G85 features optional Shading Compensation to reduce vignetting in JPEG images.

Mouse over the links above to compare thumbnails, and click on the links to load the full resolution images.

As you can see, the Panasonic G85's Shading Compensation reduced corner shading with the 12-60mm kit lens, so it's a useful feature. Shading Compensation is off by default, and is not available with all lenses. It may also produce more visible noise in the periphery at higher ISOs.

Overall, decent though not great performance for a 5x kit lens, but given Panasonic is only charging about US$100 for it when purchased with the camera, the lens is actually an amazing value.

Accuracy
Excellent coverage accuracy from the EVF and LCD monitor.

The Panasonic G85's EVF and LCD monitor proved quite accurate in record mode, showing essentially 100% coverage with our low-distortion Olympus 50mm f/2 reference lens. Excellent results here.