Panasonic GH1 Image Quality

Saturation & Hue Accuracy
Good color and hue accuracy overall, with minor oversaturation of strong reds and blues. Some issues with orange through yellow, though.

Saturation. The Panasonic GH1 pushes reds and blues a bit, and dark greens very slightly, while undersaturating lighter greens, some cyans and oranges. While the default saturation of 110.9% (10.9% oversaturated) is higher than that of the G1 (104.9%), the GH1 doesn't oversaturate as much as some consumer DSLRs. Most consumer digital cameras produce color that's more highly saturated (more intense) than found in the original subjects. This is simply because most people like their color a bit brighter than life.

Skin tones. Here, the Panasonic GH1 also did well, producing natural-looking skin tones, though just slightly on the pinkish side. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc.

Hue. The Panasonic GH1 did push cyan toward blue, red toward orange, and orange toward yellow. Shifts were relatively slight, but the net result is that colors in the orange through yellow range are less clearly delineated from each other than they would be with a camera having better hue accuracy. The yellow-toward-green shift was especially noticeable in the yellow yarn of our Still Life test image. Nonetheless, overall accuracy was still pretty good. (The blue to cyan shift is very common among the digital cameras we test; we think it's a deliberate choice by camera engineers to produce better-looking sky colors.) Hue is "what color" the color is.

Saturation Adjustment
The Panasonic DMC-GH1 lets you adjust the image saturation, contrast, and sharpness in five steps each. As can be seen below, the saturation adjustment was very subtle. We usually argue in favor of more subtle adjustments for saturation on the cameras we test, the Panasonic GH1 goes a bit too far in that direction; we'd like to see a wider range here (more steps), but still with the fine steps the GH1 currently offers.

The table above shows results with the default as well as the two "extreme" saturation settings. Click on any thumbnail above, then click again to see the full-sized image.

Exposure and White Balance

Indoors, incandescent lighting
Very good performance: Slightly warm cast with Auto, very warm with Incandescent, very good color with the Manual and 2,600 Kelvin white balance settings. Average positive exposure compensation required.

Indoors, under normal incandescent lighting, color balance was just slightly warm with the Auto white balance setting, though the Panasonic GH1 did much better than most digital SLRs in this regard. (While slightly warm, results with the Auto setting are quite acceptable, and many users will in fact prefer a slightly warm look in situations like this, to better represent the mood of the original lighting.) Results with the Incandescent setting were much warmer; the Incandescent setting looks like it might be adjusted to match professional studio lighting, a little odd for a decidedly consumer camera model. The Manual setting produced the most accurate results, though the 2,600 Kelvin setting wasn't far off the mark either, being just slightly cooler. The Panasonic GH1 required an average amount of positive exposure compensation here, at +0.3 EV. Overall color looks good, though the blue flowers look a touch purplish, probably due to the DMC-GH1's tendency to punch up reds a little. ((Many digital cameras reproduce the blue flowers here with more of a purplish tint, so the Panasonic GH1 actually performs a bit better than average here.) Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulbs, a pretty yellow light source, but a very common one in typical home settings here in the U.S.)

Outdoors, daylight
Bright colors overall, though a tendency toward high contrast under harsh lighting. Slightly below average exposure accuracy.

Outdoors, the Panasonic Lumix DMC-GH1 performed pretty well, with good color but slight overexposure in the outdoor far-field house shot. The Panasonic DMC-GH1 required a bit more than the average amount of positive exposure compensation (+1.0 EV) to keep facial tones bright on the "sunlit" portrait test, but that resulted in so many blown highlights that we opted for the +0.7EV shot for our sample image here. That left the model's face a little dark, but there were still a lot of blown highlights in her shirt. Default contrast is on the high side, but fortunately, there's a contrast adjustment to help compensate. Overall, good results here, especially when the contrast setting is turned down (see Extremes section below).

See full set of test images with explanations
See thumbnails of all test and gallery images

Resolution
Very high resolution, 1,650 ~ 1,800 lines of strong detail.

In camera JPEGs our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,650 lines per picture height horizontally, and about 1,700 lines in the vertical direction. Extinction didn't occur until about 2,700 lines horizontally and vertically. We weren't able to extract much more resolution by processing the GH1's RW2 files using Adobe Camera Raw 5.4b, but ACR did hold definition in the target lines a bit better than the camera's own JPEG conversion did, making the target lines more distinct at all high frequencies. Note that ACR 5.4b is a release candidate, and will likely be tweaked before final, as it appears to have difficulty demosaicing GH1 files with repetitive detail near the Nyquist frequency (look at the strong moire and maze patterns starting at 2,800 lines in full size ACR converted resolution chart on the right). Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail.

See full set of test images with explanations
See thumbnails of all test and gallery images

Sharpness & Detail
Good sharpness overall, though edge-enhancement artifacts on high-contrast subjects are visible. Moderate noise suppression visible in the shadows.

Sharpness. The Panasonic GH1 captures fairly sharp images overall, though a few edge enhancement artifacts are visible on high-contrast subjects such as the branches in the crop above left. Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.

Detail. The crop above right shows some moderate noise suppression artifacts in the darkest areas of the model's hair, smudging individual strands together, though quite a few strands are visible in the lighter shadows. Overall detail is better than average, but there are some odd color blotches (visible on the left edge of the crop above), that we believe may be the result of insufficient anti-aliasing filtering, and the demosaicing problems that produces. (We only noticed these in the very fine, reddish detail of the mannequin's hair, a subject that has produced this sort of artifact on other cameras, including several SLRs, in the past.) Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears.

RAW vs In-Camera JPEGs
As noted above, the Panasonic GH1 produces fairly sharp in-camera JPEGs. As is almost always the case, though, quite a bit more detail can be obtained from carefully processing RAW files than can be seen in the in-camera JPEGs. The Panasonic GH1's JPEGs are quite good straight from the camera, but it's surprising how much more detail is visible after processing in a good RAW converter. Take a look below, to see what we mean:

In the table above, mousing over a link at the bottom will load the corresponding crop in the area above, and clicking on the link will load the full resolution image.

SilkyPix appears to be a very sophisticated RAW processor that provides lots of control over the image processing it performs. In the crops above, we dialed up the sharpness setting in its demosaicing control panel somewhat (to 94), and then used a manual adjustment on its sharpening panel, starting with the "Emphatic Sharp" preset, but then dialing back the outline emphasis to 16 (from the default of 20 in that mode). We also applied unsharp masking at the output stage, with an intensity of 200% and radius of 0.3 pixel.

Adobe Camera Raw 5.4 release candidate was used for the ACR conversion version. The image was then sharpened in Photoshop using unsharp masking at 250% and radius of 0.3 pixel.

As you can see, all three RAW conversions contain a lot more fine detail than the camera JPEG, while at the same time showing fewer sharpening artifacts: The Panasonic DMC-GH1 rewards RAW shooters with really excellent detail. And the bundled SilkyPix RAW converter can give Adobe Photoshop and Camera Raw a very good run for the money, when it comes to the detail department.)

The crops above were taken from shots captured with an Olympus 14-54mm lens attached to the GH1 via a lens adapter: The 14-54mm Olympus optic is an exceptionally sharp pro-grade lens, and we wanted to see what the Panasonic GH1 could do with the best lens we had available (in this focal length range) attached to it. As it turns out, though, the kit lens that ships with the GH1 is no slouch, particularly at its wider focal lengths. See the shots below for a comparison:

The shots above were taken on different days from very slightly different positions, so the tree limbs in the background shift their position slightly relative to the house. But you can easily enough find common elements between the two to make careful comparisons. It's clear that the Olympus 14-54mm lens has a slight resolution advantage, but the Panasonic 14-140mm does remarkably well, particularly for a lens with a 10x zoom ratio.

ISO & Noise Performance
Low noise up to ISO 400, moderate to high at higher ISOs, but an improvement over the G1 at high ISOs.

The Panasonic GH1's images are quite clean at ISOs 100 and 200; very similar to the G1's. We start to see a very fine, tight "grain" pattern at ISO 400, but detail is still pretty good, with just a bit of chroma noise creeping into the shadows. The grain is slightly more evident at ISO 800, there's more chroma noise and detail starts to suffer due to noise reduction, but not as much as with the G1. At ISO 1,600, we see additional detail loss, as well as purple and yellow blotches. At ISO 3,200, noise grain is much courser and blurring stronger, resulting in a noticeable drop in detail with some obvious horizontal banding. That said, the Panasonic GH1's high-ISO images are improved over those of the earlier G1, and are generally better-looking than we've come to expect from Four-Thirds format cameras in the past. As always, see the Print Quality section below for maximum recommended print sizes at each ISO.

Extremes: Sunlit and low light tests
High resolution with good overall detail, but somewhat high default contrast and limited dynamic range. Reasonably good low-light performance, but autofocus struggled quite a bit at lower light levels.

Sunlight. The Panasonic Lumix DMC-GH1 struggled a bit with the deliberately harsh lighting of this test, as contrast was a little high at its default setting, and the dynamic range seemed limited. Although we liked the detail in the shirt better at +0.7 EV with the default contrast, we preferred the +1.0 EV exposure overall, because the exposure of the skin tone in the face was better. Depending on the photographer, you could lean one way or the other. Pros and advanced users will want to shoot darker, to hold highlight detail. For those DMC-GH1 owners that are going to want to just print an image, the +1.0 image would probably produce a better-looking print with little or no tweaking. The bottom line though, is that the GH1 had difficulty with the wide dynamic range of this shot, at least with its default settings.

Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here.)

Contrast Adjustment
As mentioned previously, the camera's limited contrast adjustment was at least some help in handling the harsh lighting.

At its lowest contrast setting, the Panasonic GH1 did a better job of preserving highlight detail, maintaining fairly natural-looking skin tones, and holding more in the shadows, but the limited dynamic range makes it perform a bit below average in this regard.

The shots above show the results of the minimum, default and maximum contrast settings. While you can see the extremes, it's pretty hard to evaluate small differences in contrast on small thumbnails like these, click on any thumbnail to go to the full-size image. That said, unlike the Saturation adjustment, the control for Contrast is not quite as subtle in its effect. It seems to basically leave the strongest highlights alone, and then apply a proportional boost to tones as it moves down the tone curve. To make the most of it in a shot like this, you'd want to drop the exposure to hold the highlights and then apply a good amount of contrast reduction (probably the maximum, the steps are pretty small).

The Panasonic GH1's contrast adjustment helps a little with the strong highlights here, but we'd really like to see more steps of this size, to cover a slightly greater range. And even with the lowest contrast setting, the dynamic range isn't terribly impressive: While dropping the exposure slightly helped the highlights, and the contrast adjustment opened up the shadows somewhat, the camera still struggles with the deliberately harsh lighting. (Which means it will also have issues with strong, direct sunlight.)

Panasonic's iExposure
The above shots are examples of Panasonic's Intelligent Exposure (or iExposure) at work. There are three levels of iExposure available: Low, Standard and High, plus Off. Like the saturation adjustment, the difference between the three levels was very subtle, however all were an improvement over the Off setting, doing a nice job of pulling detail up out of the shadows, and delivering a nice exposure overall, with good tonality in the mannequin's face, and good detail in both highlights and shadows.

Face Detection
Like most Point & Shoot cameras these days (and some DSLRs in Live View mode), the Panasonic GH1 has the ability to detect faces, and adjust exposure and focus accordingly. The GH1 does it automatically in Intelligent Auto (iAuto) mode, when a Portrait scene mode is selected, or when Face Detection AF mode is selected. As you can see from the examples above, it really works, as the image with face detection enabled is better exposed for the face. We'd prefer a slightly higher exposure as the mannequin's face is still dim, but if combined with Panasonic's Intelligent Exposure (see the example above), we believe it would deliver very nice exposures, even under very difficult lighting such as this. Panasonic says the system can detect up to 15 faces in a scene, though we did not test that claim.

Low light. The Panasonic DMC-GH1 performed reasonably well in our low light test, capturing acceptably bright images down to the lowest light level we test at, at all ISO settings. This darkest level equates to about 1/16 the brightness of average city street lighting at night, so the DMC-GH1 should be able to take well-exposed photos in almost any environment in which you can see well enough to walk around in. Automatic color balance was pretty good, something that's not a given at such low light levels. Using the default noise reduction setting, noise is low to moderate below ISO 800. At ISOs 800, 1,600 and especially 3,200, noise is rather high compared to most DSLRs these days, with moderate to strong horizontal banding detectable in darker areas. (The shape of the banding is quite interesting, as it is not straight, almost certainly a side-effect of the geometric distortion corrections the GH1 makes, as the curvature of the banding is most obvious in the corners of the frame.) That said, aside from the banding issue, the Panasonic GH1's image noise is better than what we've been accustomed to seeing from cameras with Four Thirds sensors in the past.

The camera's autofocus system was able to focus on the subject down to just below 1/4 foot-candle light level unassisted, which isn't nearly as good as most DSLRs, but is good for a camera using contrast-detect autofocus. The DMC-GH1 does have a focus-assist light option which allows it to autofocus in total darkness, as long as the subject is within range and has sufficient contrast. We heard of at least one reader complaint that his GH1 sometimes would trip the shutter without having been focused in dim lighting with the AF-assist light turned off, but didn't observe that behavior in our sample.

How bright is this? The one foot-candle light level that this test begins at roughly corresponds to the brightness of typical city street-lighting at night. Cameras performing well at that level should be able to snap good-looking photos of street-lit scenes.

NOTE: This low light test is conducted with a stationary subject, and the camera mounted on a sturdy tripod. Most digital cameras will fail miserably when faced with a moving subject in dim lighting. (For example, a child's ballet recital or a holiday pageant in a gymnasium.) Thanks to their phase-detect AF systems, digital SLRs tend to do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects. The GH1 uses contrast-detect autofocus, as is found in most point & shoot cameras, so its low-light focusing ability is less than that of SLRs with phase-detect systems. That said, though, the larger, more sensitive pixels of the GH1's sensor do better under dim lighting than do the tiny pixels of most point & shoots, (A useful trick is to just prop the camera on a convenient surface, and use its self-timer to release the shutter. This avoids any jiggling from your finger pressing the shutter button, and can work quite well when you don't have a tripod handy.)

Print Quality
Great print quality, good color, sharp 13x19 inch prints from camera JPEGs, 16x20 inch ones from RAW files. (Even 20x30 prints from RAW are very usable for wall display.)

Like the G1 before it, the Panasonic GH1's printed output is really impressive, but to get the best results, you really need to work from its RW2 RAW files. In-camera JPEGs are a little soft looking, due in part to conservative in-camera sharpening, but likely also in part to noise-reduction processing, even at low ISO settings. SilkyPix (the RAW processing software bundled with the Panasonic GH1) and Adobe Camera Raw both reveal quite a bit more fine detail, particularly in areas of subtle subject contrast. Sharpening the in-camera JPEGs helps some, but never brings out the detail in lower-contrast regions that SilkyPix and ACR find in the RW2 files.

Working from RAW files, we felt that 20x30 inch prints would be entirely acceptable for display at any normal viewing distance: If we got up close and squinted, they were a little soft, but at normal viewing distances of more than a foot or so, they looked crisp and very detailed. The in-camera JPEGs might pass as 20x30s if viewed from a little distance, but looked entirely fine at 16x20, and sharp indeed when printed at 13x19.

ISO 800 shots made excellent 13x19 inch prints, just slightly soft, and with a little chroma noise to be seen in the shadows. (A good third-party noise reduction program would likely make short work of the little we saw.) ISO 800 prints at 11x14 inches were tack-sharp. At ISO 1,600, where we felt that 8.5x11 was about the limit for the G1, we think most people would be happy with prints from the Panasonic GH1's ISO 1,600 shots at 11x14. At ISO 3,200, though, chroma noise becomes much more of an issue, making even 5x7 inch prints problematic if they have much shadow area and large areas of flat tints. But if you crank the noise reduction setting up to +2, 5x7 inch output looks pretty good, albeit still with some chroma noise visible in the shadows. (Personally, we'd not push them to 8.5x11 output, but some folks might. The results at 3,200 don't seem to be as far ahead of those of the G1 as they do at lower ISO settings.)

Part of what makes the Panasonic GH1's high-ISO shots print so well is that what noise is there is very fine-grained, so it tends to drop out quite nicely in the printing process. Looking at its images under high magnification, in areas were there's lots of subject detail (so the anti-noise processing will be dialed back somewhat), it's apparent that Panasonic has opted to leave a fair bit of fine-grained luminance noise in the final images, rather than trying to flatten it out. This can make parts of its images look rough when you're pixel-peeping at 100% or larger on-screen; but when printed, the images look great, with plenty of detail, and only modest amounts of noise.

We also found the Panasonic GH1's prints very appealing when it came to color. Colors were bright and attractive, without appearing overdone. If there was any weak point, it might be in the GH1's handling of colors in the yellow to yellow-green portion of the spectrum. Yellows were shifted slightly toward green, while the yellow-greens were shifted a bit toward yellow. The net effect wasn't anything like a glaring problem, it's just something we noticed in the colors of the embroidery threads in our Still Life target.

All in all, very impressive print quality from a little camera; The verdict is clear, you no longer have to carry a full-size SLR to get excellent print quality.

Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon Pro9000 studio printer, and on the Canon iP5200 here in the office. (See the Canon Pixma Pro9000 review for details on that model.)