Panasonic G3 Image Quality
Panasonic G3 Image Quality
Saturation & Hue Accuracy
Good color and saturation levels over most of the spectrum, with improved hue accuracy over prior models.
Skin tones. Here, the Panasonic G3 struggled a bit, producing Caucasian skin tones that were pinkish with patches that contained too much yellow or orange, even when manual white balanced was used. This was especially evident in our indoor shots. 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 G3 pushed cyan toward blue slightly (but much less so than most cameras), red toward orange, orange toward yellow and yellow toward green. Some greens were also pushed toward yellow. In the orange through yellow range, shifts weren't as pronounced as previous Panasonic CSCs, and with an average "delta-C" color error of 5.53, overall hue accuracy was pretty good. Even better, the orange-yellow shifts are significantly mitigated by working with RAW files and using a good-quality RAW converter. Adobe Camera Raw does not support the G3's RAW files yet, but SilkyPix was able to do a better job with color accuracy than the camera. Delta-C color error using SilkyPix defaults improved to 4.53, which is very good. Hue is "what color" the color is.
Photo Style Modes
The Panasonic G3 offers six preset Picture Style modes. You can adjust contrast, saturation, sharpness and noise reduction for any of the modes, and then save your settings as one custom option.
Mouse over the links above to see the effect of the presets on our Still Life target. You can click on a link to load the full resolution image.
The Panasonic G3 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, but like previous Panasonics, the G3 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 G3 currently offers.
|Saturation Adjustment Examples|
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.
|See full set of test images with explanations
See thumbnails of all test and gallery images
Exposure and White Balance
Indoors, incandescent lighting
Slightly warm cast with Auto, very warm with Incandescent, but good color balance with the Manual and 2,600 Kelvin white balance settings. Slightly higher than average positive exposure compensation required.
|Auto White Balance
|Incandescent White Balance
|Manual White Balance
|2,600 Kelvin White Balance
Indoors, under normal incandescent lighting, color balance was just slightly warm with the Auto white balance setting, though the Panasonic G3 did much better than most digital SLRs in this regard. (While slightly warm, results with the Auto setting were quite acceptable, and many users 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 consumer camera model. The Manual and 2,600 Kelvin settings produced very similar results with the most accurate white balance and very neutral grays, though some colors like the mannequin's hair and skintones were pushed toward yellow/orange. The Panasonic G3 required +0.7 EV exposure compensation here, which is a bit higher than the average of +0.3 EV for this shot among the cameras we've tested. Exposure is a little bright at +0.7 EV, but we found +0.3 EV a bit dark. +0.5 EV might have been ideal. (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.)
Somewhat warm colors overall, with a tendency toward high contrast under harsh lighting. About average exposure accuracy.
|Manual White Balance,
|Auto White Balance,
Outdoors, the Panasonic G3 performed fairly well with good exposures though colors were a touch warm. Facial skintones had too much orange/yellow with Auto White Balance, but Manual White Balance performed better. The Panasonic Lumix G3 required an average amount of positive exposure compensation (+0.7 EV) to keep facial tones reasonably bright in our "Sunlit" Portrait test, which led to some blown highlights in her shirt and flowers. Default contrast is on the high side, but fortunately, there's are contrast and dynamic range adjustments to help compensate. Overall, fair results here, especially when the contrast setting is turned down (see Extremes section below).
Very high resolution, 2,100 ~ 2,200 lines of strong detail.
|Strong detail to
~2,200 lines horizontal
|Strong detail to
~2,100 lines vertical
In camera JPEGs our laboratory resolution chart revealed sharp, distinct line patterns down to about 2,200 lines per picture height horizontally, and about 2,100 lines in the vertical direction. Extinction of the pattern didn't occur until about 3,000 lines horizontally and vertically. Adobe Camera Raw, our "reference" converter does not yet support the G3's .RW2 files so we can't tell if RAW files contain significantly more resolution, but we suspect the camera is doing a pretty good job at extracting most of the available detail. 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.
Sharpness & Detail
Very good sharpness overall, though edge-enhancement artifacts are visible on high-contrast subjects. Very good detail, but moderate noise suppression visible at even the base ISO.
|Very good definition of high-contrast
elements with some visible
|Subtle detail: Hair
Noise suppression tends to blur
detail in areas of subtle contrast.
Sharpness. The Panasonic G3 captures sharp, detailed images overall, though with some edge enhancement artifacts visible on high-contrast subjects such as the branches in the crop above left. Finer detail with lower contrast such as the pine needles show fewer sharpening artifacts. Very good results here. 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 model's hair even at ISO 160, smudging individual strands together, though quite a few strands are visible. Overall detail is very good, but like previous Panasonic models, there are some odd color blotches (see the JPEG crop at right) that we believe may be the result of insufficient anti-aliasing filtering, and the aliasing/demosaicing problems that it produces. (We also saw these with previous G-series cameras and it's something that we've seen with a number of other cameras in the past, including several SLRs.) The blue/gray blotches are not present in SilkyPix converted files and we'd expect the same for Adobe Camera Raw. (However, ACR does not support the G3 yet so we can't show you an ACR conversion.) 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.
The Panasonic G3 offers four levels of "Intelligent Resolution", which essentially sharpens fine detail while leaving areas with little or no detail (such as a cloudless sky) untouched to keep visible noise to a minimum. To see how well it works, compare the crops below at each setting.
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.
As you can see, fine detail has progressively stronger sharpening applied as the setting is increased, while the noise in the sky is not affected. The increased sharpening and noise reduction does tend to coarsen and blur fine detail at higher settings, though. The pine needles in the trees behind the house are a good illustration of this effect. Still, we think most users will be pleased with the extra "pop" in apparent detail Intelligent Resolution provides to JPEGs, at least for natural subjects.
RAW vs In-Camera JPEGs
As noted above, the Panasonic G3 produces sharp, detailed in-camera JPEGs. As is almost always the case, though, quite a bit more detail can often be obtained from carefully processing RAW files than can be seen in the in-camera JPEGs.
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 3.1 SE (the RAW converter Panasonic bundles with their RAW-capable cameras) is pretty sophisticated in the controls it provides for tweaking your photos. In the SilkyPix crops above, we turned the in-application sharpening control down to zero and used only its output unsharp masking, which we set to 350%, a radius of 0.3 pixels, and a threshold of 0. File output is actually a logical place to apply unsharp masking, as you'll want to use different sharpening settings for printing at different sizes.
We found fine detail to be a little smudged from SilkyPix, so we did a second conversion with noise reduction turned all the way down to see if that made a difference. As you can see, the SilkyPix conversions have higher default contrast and colors are rendered somewhat differently than the camera. Both conversions show more noise than the JPEG, yet they don't show the significant increase in fine detail we expected. We think we'll be able to extract more detail using a good third-party converter such as Adobe Camera Raw. We'll try to add an Adobe Camera Raw conversion, once ACR supports the G3's RAW files.
ISO & Noise Performance
Low to moderate noise up to ISO 800 with very good detail. Some noise reduction already evident at base ISO, though detail vs noise is much better than the G2.
Default Noise Reduction
|ISO 160||ISO 200||ISO 400|
|ISO 800||ISO 1,600||ISO 3,200|
The Panasonic G3's images look fairly clean through ISO 400, though fine detail is already impacted by default noise reduction at ISO 160. Some chroma noise is also visible in the shadows and darker strands of hair at low ISOs. Skintones and hair also suffer from too much yellow/orange push in these shots, despite the neutral color balance seen in the WhiBal card. As mentioned previously, demosaicing errors in the hair cause what looks like blue/gray chroma noise as well at low ISOs, something we've seen in previous Panasonics as well as some other brands. They disappear at ISO 800 and above, a result of stronger chroma noise reduction. ISO 800 shows a jump in luminance noise, but it's fine-grained, leaving a surprising amount of detail intact. ISO 1,600 is noticeably softer due to stronger noise reduction, but detail is still pretty good. ISO 3,200 is softer still, with shadows picking up a purple tint along with hints of horizontal banding. High contrast detail is still very good, though. Fine detail at ISO 6,400 is soft and mushy, though some individual strands of hair can still be made out, and there's quite a bit of luminance noise to be seen in flat areas, but this is to be expected at such a high ISO. Overall, a very good balance between noise and detail, and a big improvement over the G2 despite the G3's smaller photosites. The G3's JPEG noise performance is slightly better than the more expensive GH2, and even rivals some APS-C models.
We're of course pixel-peeping to an extraordinary extent here, since 1:1 images on screen have little to do with how those same images will appear when printed. See the Print Quality section below for our evaluation of maximum print sizes at each ISO setting.
A note about focus for the indoor portrait shot: We shoot this image at f/4, usually using one of three very sharp reference lenses (70mm Sigma f/2.8 macro for most cameras, 60mm f/2.8 Nikkor macro for Nikon bodies without a drive motor, and Olympus Zuiko 50mm f/2.0 for Four Thirds and Micro Four Thirds bodies). To insure that the hair detail we use for making critical judgements about camera noise processing and detail rendering is in sharp focus at the relatively wide aperture we're shooting at, the focus target at the center of the scene is on a movable stand. This lets us compensate for front- or back-focus by different camera bodies, even those that lack micro-focus adjustments. This does mean, though, that the focus target itself may appear soft or slightly out of focus for bodies that front- or back-focused with the reference lens. We know this; if you click to view the full-size image for one of these shots and notice that the focus target is fuzzy, you don't need to email and tell us. :-) The focus target position will have been adjusted to insure that the rest of the scene is focused properly.
Extremes: Sunlit and low light tests
High resolution with good overall detail, but somewhat high default contrast and limited dynamic range. Good low-light performance.
|+0.3 EV||+0.7 EV||+1.0 EV|
Sunlight. The Panasonic Lumix DMC-G3 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 somewhat limited. Although skin tones in the face are a bit dark at +0.7 EV with the default contrast, we preferred it to +1.0 EV exposure overall, because there were fewer clipped highlights. 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 Panasonic G3 owners that are going to want to just print an image with little or no tweaking, the +1.0 EV image would probably produce a better-looking uncorrected in this situation. The bottom line though, is that the Panasonic G3 had difficulty with the wide dynamic range of this shot, at least with its default contrast settings.
Imatest dynamic range analysis (see graph at right, and click on the image for a larger version) for an in-camera JPEG file with a nominally-exposed density step target (Stouffer 4110), at default settings and base ISO shows 10 f-stops of total dynamic range, with about 7.0 f-stops at the "High" quality level. Compared to the Panasonic G2, the G3 scored slightly higher at the "High" quality level (7.02 vs 6.68 f-stops), but lower in total dynamic range (10 vs 10.8 f-stops).
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.)
As mentioned previously, the camera's limited contrast adjustment was at least some help in handling the harsh lighting.
|Contrast set to lowest,
|Contrast set to lowest,
At its lowest contrast setting, the Panasonic G3 did a slightly better job of preserving highlight detail while maintaining reasonable skin tones, though it helped more with bringing out the shadows and darker midtones. Overall, the camera's limited dynamic range makes it perform a bit below average in this situation.
|Contrast Adjustment Examples|
The table above shows results with the default as well as the two "extreme" contrast settings. Click on any thumbnail above, then click again to see the full-sized image. 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, as the steps are pretty small).
The Panasonic G3's contrast adjustment helps with the strong highlights and deep shadows here, but we'd really like to see more steps of this size, covering a slightly greater range. And even with the lowest contrast setting, the dynamic range isn't terribly impressive.
Panasonic's "Intelligent Dynamic Range"
The above shots are examples of Panasonic's Intelligent Dynamic Range (or iDynamic) at work, with +0.7 EV exposure compensation. iDynamic appears to be a more advanced version of iExposure, and is said to be capable of reducing both blocked shadows and clipped highlights. It's currently only found on the G3, GH2 and GF2 system cameras. iExposure, which worked by raising sensitivity in dark areas to bring out more detail is no longer offered. There are three levels of iDynamic available on the G3: Low, Standard and High, plus Off. iDynamic is automatically invoked in iAuto mode and manually selectable in PASM modes. All shots above used the base ISO of 160 equivalent with an exposure compensation of +0.7 EV. (We found the images were too dark at default exposure.)
For our Outdoor Portrait shots above, all three settings were an improvement over the Off setting, pulling detail out of the shadows and delivering a progressively brighter exposure without clipping any additional highlights. Shadow noise is more visible, but that's to be expected when boosting shadows. As you can see from the histograms, there were some highlights blown to begin with at +0.7 EV exposure, and iDynamic did work to reduce highlight clipping slightly, but not as much as we'd like. Bottom line, though, iDynamic seems to provide a useful extension to the practical dynamic range of the Panasonic G3. (It's not likely increasing the technically defined dynamic range of the sensor any, but it can make for much more usable/printable images when working under tough lighting conditions.)
As you can see, iDynamic brightened the shadows in our Far-field House shot, though again it looks as though little attempt is made to reduce existing highlight clipping. (In fact, slightly more highlights were clipped in the bright white trim with iDynamic enabled versus off.) The Standard and High settings produced results very similar to the Low setting in this case.
|Off at 0 EV||On at 0 EV||iAuto at 0 EV|
Like most point & shoot cameras these days (and most DSLRs in Live View mode), the Panasonic Lumix DMC-G3 has the ability to detect faces, and adjust exposure and focus accordingly. The G3 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, face detection along worked fairly well, as the image with it enabled (center) is much better exposed for the face than the default exposure (left). iAuto mode (right) selected Portrait mode which also enabled face detection according to EXIF metadata, however it ended up focusing behind the mannequin's face and slightly overexposing the face. Also note the strong yellow/orange skintones which we had hoped would be more natural looking in Portrait mode.
Low Light. The Panasonic DMC-G3 performed reasonably well in our low light test, capturing 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 Panasonic G3 should be able to take well-exposed photos in almost any environment in which you can see well enough to walk around in. As is often the case, the G3's auto exposure system struggled to produce a good exposure the lowest light levels, so we used manual mode for these shots.
Automatic white balance was very good (just slightly cool), something that's not a given at such low light levels. Using the default noise reduction setting, noise was pretty low up to ISO 1,600, though some chroma noise is visible in darker areas already at base ISO. Interestingly, with NR turned all the way down and Long Shutter NR turned off (right-most column), ISO 160 shots have a sprinkling of coarse luminance noise that almost have a flaky appearance, but at ISOs 200 and 400 the "flakes" appear a clusters of bright chroma noise. We wouldn't be surprised if revised firmware was released to address this, as these shots were taken with early firmware (Ver 0.2). At ISOs 3,200 and above, noise was higher but the G3's noise reduction processing does a very good job at holding on to detail while keeping noise in check. Hints of horizontal banding are visible at higher ISOs and lower light levels, but that's not unusual and it's not nearly as evident as some earlier G-series models. We did not notice any issues with hot pixels, though we spotted a few at lower ISOs and light-levels. Note that the G3 has a pixel mapping function (called "Pixel Refresh") to map out hot pixels, though we didn't try that feature.
The camera's autofocus system struggled a bit in low light, as it was only able to focus on our subject down to between 1/2 and 1/4 foot-candle unassisted with the kit lens at f/3.5, which is a bit disappointing even for a camera using contrast-detect autofocus. The Panasonic G3 does however 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.
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 G3 uses contrast-detect autofocus, as is found in most point & shoot cameras, so its low-light focusing ability is less than that of some SLRs with phase-detect systems. That said, though, the larger, more sensitive pixels of the G3'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.)
Pretty impressive print quality, easily rivaling the Canon 60D.
ISO 160 shots look great at 20 x 30 inches, with good color and excellent detail. One issue does emerge at this ISO, though, captured in our INB indoor incandescent shot, where our model's red hair shows some demosaicing errors, which appear as blue/gray artifacts, and don't become negligible until the image is printed at 11 x 14 inches. Processing RAW images on a computer does not exhibit the error, by the way.
ISO 200 shots are also great at 20 x 30, with excellent color and detail. The demosaicing error is still present, but less noticeable.
ISO 400 shots, too, look surprisingly good at 20 x 30 inches. There's the slightest softening, but you have to get close and squint to see it. The demosaicing error is eliminated by the noise suppression system.
ISO 800 shots finally start to show a little more softening, but we'd still call it usable at 20 x 30 inches. There is some very slight luminance noise in the shadows, but very little. All of this returns to impressive crispness when printed at 16 x 20 inches.
ISO 1,600 images are usable at 16 x 20, though low-contrast detail in reds has begun to disappear more noticeably, and there's more noise in darker areas. Prints at 13 x 19 look great.
ISO 3,200 images usable for wall display at 13 x 19, and fine for close viewing at 11 x 14. Luminance noise in the shadows continues to increase, but it's not bad at all. Color also dims more noticeably at this setting, with a slight green cast coming into yellows, but not nearly as bad as it has on past Panasonic cameras, including the GH2.
ISO 6,400 shots are usable at 8 x 10 and good at 5 x 7. That green shift in the yellows continues, but is still better controlled than any previous high-end Panasonic camera.
Overall, the Panasonic G3's JPEG images print amazingly well, and challenging any concern that Micro Four Thirds sensors would continue to lag in image quality behind their APS-C competition. While upcoming SLRs may do better, it's clear that Panasonic has met the challenge in the meantime. Very impressive!
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 Mark II studio printer, and on the Canon Pixma MP610 here in the office. (See the Canon Pixma Pro9000 Mark II review for details on that model.)
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