Panasonic GH3 Exposure

Saturation & Hue Accuracy
About average saturation levels, with slightly below average hue accuracy.

Saturation. The Panasonic GH3 produces typical saturation levels compared most cameras at default settings. The Lumix GH3 pushes dark red, purples, and dark green slightly, and darker blues a fair bit, but undersaturates yellow, aqua and cyan. Average saturation is 108.7% (8.7% oversaturated) at the base ISO of 200, which gradually drops as ISO rises to 6,400, but drops a little quicker at ISOs 12,800 and 25,600, ending up at 102%. 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 GH3 does fairly well, producing natural-looking Caucasian skin tones with a push towards pink when Auto white balance is used, giving a healthy appearance. Darker skin tones have a small nudge towards red, but overall results are pretty good here. 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 GH3 shifts orange toward yellow and cyan toward blue, but most other shifts are quite minor. The camera's average "delta-C" color error after correction for saturation is 5.71 for JPEGs at the base ISO of 200 (125 is an extended ISO, as is 25,600). That's just a bit below average these days, and color error remains fairly stable throughout the ISO range. Hue is "what color" the color is.

Saturation Adjustment
The Panasonic GH3 lets you adjust image saturation in eleven steps each, giving unusually fine control over the effect. The saturation setting also has little effect on contrast, which is good.

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
Warm colors with Auto and Incandescent white balance setting. Best color balance with the Manual setting, a little cool with 2,600 Kelvin. Average positive exposure compensation required.

Indoors, under normal incandescent lighting, color balance is quite warm with the Auto white balance setting. Results with the Incandescent setting are also much too warm, with a slightly stronger orange-yellow cast. The Manual setting produced very accurate results, while the 2,600 Kelvin setting which should match the color temperature of our lights is a bit too cool with a slight bluish cast. The Panasonic GH3 required +0.3 EV exposure compensation here, about average for this shot. (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
Slightly cool colors overall, with a tendency toward high contrast under harsh lighting. About average exposure accuracy.

Outdoors, the Panasonic GH3 performed pretty well, with good though slightly cool color in the Far-field shot. Skintones are reasonably realistic in our "Sunlit" Portrait shot, with a healthy-looking push of pinks and reds which is preferable to too flat or yellow. Exposure accuracy is about average, as the camera required +0.7 EV compensation for our "Sunlit" Portrait shot to keep facial tones reasonably bright. That's average for this shot, but it led to a few blown highlights while leaving some dark shadows, though performance here is better than average particularly for a Micro Four Thirds sensor. The default exposure is a bit dim for the Far-field shot, but there are very few blown highlights, though there are some deep shadows that are a bit noisy. Default contrast is on the high side, but that's how most consumers prefer their photos.

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

Resolution
Very high resolution, ~ 2,300 lines of strong detail.

In camera JPEGs, our laboratory resolution chart reveal sharp, distinct line patterns to about 2,300 lines per picture height horizontally, and about 2,300 lines in the vertical direction. (Some might argue for higher, but aliasing artifacts begin to appear before that.) Complete extinction of the pattern didn't occur until about 3,100 lines horizontally and to 3,100 lines vertically. We weren't able to extract significantly more high-contrast resolution by processing the Panasonic GH3's RW2 file using Adobe Camera Raw, and the ACR conversion also shows some color moiré which is practically nonexistent in the camera JPEG.

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
Very good sharpness overall, with just minor edge-enhancement artifacts on high-contrast subjects. Moderate noise suppression visible in the shadows even at base ISO.

Sharpness. The Panasonic GH3 captures sharp, detailed images overall. Some minor edge enhancement artifacts are visible on high-contrast subjects such as the "halos" along the thicker branches and pine cones in the crop above left, but default sharpening here is fairly conservative compared to more consumer-oriented models. 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 the effect of noise suppression in the form of smudging of individual strands together in the darker areas of the model's hair, as well as in areas with low local contrast. Processing RAW files with a good converter can produce much improved detail and can also reduce noise reduction and demosaicing artifacts, as can be seen in the ACR converted RAW crop at right. (Mouse over the links to compare.) 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.

Intelligent Resolution
The Panasonic GH3 offers four levels of "Intelligent Resolution," which essentially sharpens fine detail and outlines, while reducing noise in areas with little or no detail (such as a cloudless sky). 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 contained in and around the lettering on the bottle has progressively stronger local sharpening applied as the setting is increased, while noise in flatter areas that would normally be emphasized with standard, global sharpening is actually reduced. Sharpening halos are however more visible at higher settings. According to Panasonic, the Extended setting is designed to produce more natural results when making large prints.

RAW vs In-Camera JPEGs
As noted above, the Panasonic GH3 produces sharp in-camera JPEGs with good detail, though default noise reduction is a bit high at base ISO. As is almost always the case, quite a bit more detail can be obtained from carefully processing RAW files than can be seen in the in-camera JPEGs, with fewer sharpening artifacts to boot. 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.

The first crop from the left is from an in-camera Fine JPEG at default settings. The second is a raw file converted with SilkyPix 3.1 SE (the converter/editor Panasonic bundles with their RAW-capable cameras), using default settings. The third crop is also a RAW conversion done with SilkyPix but with noise reduction and sharpening set as low as they go within the editor, and then sharpened using SilkyPix's output unsharp masking feature set to 300%, a radius of 0.3 pixels, and a threshold of 0. Adobe Camera Raw 7.2 was used for the ACR conversion at right. Default settings were used for conversion, though no sharpening was applied in ACR. The image was then sharpened in Photoshop using the same sharpening settings as we used with SilkyPix.

As you can see, the in-camera JPEG contains pretty good fine detail. SilkyPix however had trouble with the pine needles, flattening them out and making them look reminiscent of a watercolor painting when viewed up close. It's likely doing some fairly heavy-handed noise reduction under the hood which can't be disabled. The results we got using SilkyPix are a bit disappointing, but we must confess we didn't experiment with different settings for very long, so you may be able to do better. The ACR conversion extracted the most detail, but also shows more noise, especially in areas with little detail such as the sky. You can always turn up the luminance noise reduction (default of zero was used here), or process the files in your favorite noise reduction program or plugin if you find the noise objectionable. Bottom line, though, as is usually the case shooting in RAW mode provides better detail, color, and control than in-camera JPEGs when using a good converter.

ISO & Noise Performance
Very good high ISO performance for a Micro Four Thirds model.

The Panasonic GH3's images are detailed and pretty clean at ISOs 125 through 400, with only minor luminance and chrominance noise visible in the shadows. ISO 800 shows stronger noise reduction efforts as well as more chroma noise, blurring some very fine detail in the process, though overall detail remains very good. ISO 1,600 is of course a little softer with more noticeable chroma and luma noise, but still pretty good. What looks to be a sudden increase in sharpening likely to make up for stronger noise reduction makes luminance noise more obvious with a peppering effect at ISO 3,200. At ISO 6,400. much stronger noise reduction kicks in reducing the frequency of the peppered effect, but with a large hit to fine detail. Chroma noise in the form of purple blotching in shadows and midtones is also quite noticeable at this ISO. ISO 12,800 is worse as you'd expect, with more noticeable yellow and purple chroma noise, and obvious sharpening artifacts that give the image an almost crystalline appearance. These artifacts are very noticeable and distracting at ISO 12,800, along with much stronger chroma noise in the form of purple and yellow blotches. It's hard to tell from the crop, but image quality at ISO 25,600 is pretty bad with strong luma and chroma noise along with heavy blurring, leaving little fine detail. Color balance also shifts toward green at the highest ISOs.

Overall, though, high ISO performance is very good for a Micro Four Thirds model, but still trails a bit compared to the best APS-C models. We're of course pixel-peeping to an extraordinary extent here, since 1:1 images on an LCD 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 this 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, dynamic range and low light tests
Somewhat high default contrast but good dynamic range. Good low-light performance.

Sunlight. The Panasonic GH3 did fairly well with the deliberately harsh lighting of this test. Contrast is a little high at its default setting, but dynamic range is good. We felt the +0.7 EV exposure is the best compromise here. Although skin tones around the eyes are a bit dark, we prefer it to the +1.0 EV exposure overall, because there are very few clipped highlights. It's really the photographer's choice here as to which direction to go in. For those Panasonic GH3 owners that are going to want to just print an image with little or no tweaking, the +1.0 image would probably produce a better-looking face uncorrected. The bottom line though, is that the Panasonic GH3 performed well with the wide dynamic range of this shot, much better than prior models.

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.)

Dynamic Range Analysis
A key parameter in a digital camera is its Dynamic Range, the range of brightness that can be faithfully recorded. At the upper end of the tonal scale, dynamic range is dictated by the point at which the RGB data "saturates" at values of 255, 255, 255. At the lower end of the tonal scale, dynamic range is determined by the point at which there ceases to be any useful difference between adjacent tonal steps. Note the use of the qualifier "useful" in there: While it's tempting to evaluate dynamic range as the maximum number of tonal steps that can be discerned at all, that measure of dynamic range has very little relevance to real-world photography. What we care about as photographers is how much detail we can pull out of the shadows before image noise becomes too objectionable. This, of course, is a very subjective matter, and will vary with the application and even the subject matter in question. (Noise will be much more visible in subjects with large areas of flat tints and subtle shading than it would in subjects with strong, highly contrasting surface texture.)

What makes most sense then, is to specify useful dynamic range in terms of the point at which image noise reaches some agreed-upon threshold. To this end, Imatest computes a number of different dynamic range measurements, based on a variety of image noise thresholds. The noise thresholds are specified in terms of f-stops of equivalent luminance variation in the final image file, and dynamic range is computed for noise thresholds of 1.0 (low image quality), 0.5 (medium image quality), 0.25 (medium-high image quality) and 0.1 (high image quality). For most photographers and most applications, the noise thresholds of 0.5 and 0.25 f-stops are probably the most relevant to the production of acceptable-quality finished images, but many noise-sensitive shooters will insist on the 0.1 f-stop limit for their most critical work. A full discussion of all the data Imatest produces is really beyond the scope of this review: Visit the Imatest website for details of what the program measures, how it performs its computations, and how to interpret its output.

JPEG. The graph at right (click for a larger version) was generated using Imatest's dynamic range analysis for an in-camera Panasonic GH3 JPEG file with a nominally-exposed density step target (Stouffer 4110). At default settings and native base ISO of 200, the results show 11.3 f-stops of total dynamic range, and 9.14 f-stops at the "High" quality level. From the chart in the top left, we can see roll-off at the highlight end of the tone curve is gradual, but for shadows it isn't quite as well-behaved, which could lead to some visible gradation in very deep shadows. Still, these scores are actually very good for a Micro Four Thirds model, very similar to the Olympus E-M5's. Note, that this measurement has a margin of error of about 1/3 f-stop, so differences of less than 0.33 can be ignored when comparing results to other models.

Raw. The graph at right is from the same Stouffer 4110 stepchart image captured as a raw (.RW2) file, processed with Adobe Camera Raw using the Auto setting, then tweaked from there for best results. As can be seen, the score at the highest quality level increased insignificantly compared to the in-camera JPEG, to 9.28 from 9.14 f-stops, while total dynamic range increased more dramatically from 11.3 to 12.8 f-stops with a better behaved tonal curve at the shadow end. The results here are very good for a Micro Four Thirds model and slightly better than the Olympus E-M5, but still a bit lower than leading APS-C models. It's worth noting here is that ACR's default noise reduction settings reduced overall noise somewhat (see the plot in the lower left-hand corner) relative to the levels in the in-camera JPEG, which would tend to boost the dynamic range numbers for the higher quality thresholds.

Contrast Adjustment
The camera's contrast adjustment was at least some help in handling the harsh lighting.

The Panasonic GH3's lowest contrast setting does a good job bringing out detail in the shadows and darker midtones, but it does little did little to preserve clipped highlight detail in the "Sunlit" Portrait shot. (The default Far-field shot had few highlights clipped to begin with.) Overall, pretty good performance.

Like saturation, the Panasonic GH3 offers 11(!) contrast settings, providing more than the usual latitude in this adjustment. 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.

Face Detection
Like most cameras these days, the Panasonic GH3 has the ability to detect faces (up to 15 in a scene), and adjust exposure and focus accordingly. As you can see from the examples above, face detection improved exposure in Aperture Priority at f/8, but iAuto mode really performed well where the camera had control over aperture, and automatically applied Intelligent D-Range.

Panasonic's Intelligent Dynamic Range
The above shots are examples of Panasonic's Intelligent Dynamic Range Control (or iD-Range) at work, with no exposure compensation. Note that the camera does not take multiple shots and merge them as HDR mode does (see below). It's a system that adjusts local contrast and exposure more akin to Nikon's Active D-lighting, Canon's Automatic Lighting Optimization or Sony's Dynamic Range Optimization.

There are three levels of iD-Range available on the Panasonic GH3: Low, Standard and High, plus Off. It's automatically invoked in iAuto and some scene modes and manually selectable in PASM modes. Here, the camera had sufficient native dynamic range that it managed to avoid clipped highlights without the help of iDynamic, so the settings had little effect.

HDR mode
Here, you can see the Panasonic GH3's High Dynamic Range mode at work with our Far-field shot. HDR mode takes three images at different exposures and combines them to increase dynamic range. Mouse over the links, and click on them the view the full resolution files. Notice the double images and ghosting of objects or people moving between frames. Also notice the angle of view is narrower in the HDR image, likely because the image has been cropped and upsized during the alignment process.

Low Light. The Panasonic Lumix DMC-GH3 performed well in our low light tests, able to capture bright images down to the lowest light level we test at, at all ISO settings. The darkest level equates to about 1/16 the brightness of average city street lighting at night, so the Panasonic GH3 should be able to take well-exposed photos in almost any environment in which you can see well enough to walk around in.

Using default noise reduction setting, noise is well-controlled up to ISO 3,200. Some very minor horizontal banding (pattern noise) is visible in the shadows at very high ISOs and lower light levels, but nothing unusual. We didn't notice any significant issues with hot pixels or heat blooming.

Automatic color balance was a little cool particularly at lower light levels, but not bad.

The camera's autofocus system was able to focus on our subject down to below the 1/16 foot-candle light level unassisted with an f/2.8 lens which is excellent, especially for a camera with contrast-detect autofocus. The Panasonic GH3 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.

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 GH3 uses contrast-detect autofocus, as is found in most point & shoot cameras, so its low-light focusing ability may be less than that of some SLRs with phase-detect systems. That said, though, the larger, more sensitive pixels of the GH3'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
Very good 24 x 36 inch prints at ISOs 125/200; ISO 1600 capable of a nice 13 x 19; ISO 6400 prints a good 5 x 7.

ISO 125/200 images are excellent at 24 x 36 inches, with good colors and nice detail. 36 x 48 inch prints are also suitable for wall display purposes.

ISO 400 prints look quite good at 20 x 30 inches, with wall display prints possible up to 30 x 40 inches.

ISO 800 yields a nice 16 x 20 inch print. 20 x 30s are fine for less critical applications, but there is some minor luminance noise apparent in the shadowy areas of our test target, and some of the reds are a bit on the soft side.

ISO 1600 is capable of a good 13 x 19 inch print. There is some loss of contrast in our target red swatch here, but this is quite common for most cameras as ISO rises.

ISO 3200 prints are good at 8 x 10 inches, although most all contrast is lost in our red fabric swatch and there is some minor grain in the shadows. Colors are beginning to be slightly muted as well, but enough color detail is preserved for good prints.

ISO 6400 produces a nice 5 x 7, if just a bit muted in color. 8 x 10s are also OK here for less critical applications.

ISO 12,800 has a bit too much apparent grain across the image and a decline in overall color saturation to be called good at 4 x 6, but may still be usable in certain situations where an aged and grainy look is desired.

ISO 25,600 does not print a usable 4 x 6 and is best avoided.

The Panasonic GH3 certainly holds its own in the print quality department, yielding high quality 24 x 36 inch prints at base ISO and ISO 200. This quality is maintained nicely at ISO 800 with relatively large prints for this sensor size, and allows for good 8 x 10s up to ISO 3200. This performance is not quite as good as many current APS-C cameras, and also not quite on par with one of its bigger four-thirds rivals the Olympus OM-D E-M5, but for the most part it only falls behind by a print size at some ISOs, so is still in the same general ballpark for overall image 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 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.)