Panasonic GH4 Exposure
Panasonic GH4 Image Quality
Saturation & Hue Accuracy
Fairly typical mean saturation levels, though saturation drops noticeably at high ISOs. About average hue accuracy.
|In the diagram above, the squares show the original color, and the circles show the color that the camera captured. More saturated colors are located toward the periphery of the graph. Hue changes as you travel around the center. Thus, hue-accurate, highly saturated colors appear as lines radiating from the center. Mouse over the links to compare results at different ISOs, and click on the links for larger images.|
Saturation. The Panasonic GH4 produces images with fairly typical mean saturation levels compared to most cameras at default settings. Mean saturation is 108.9% (8.9% oversaturated) at the base ISO of 200, but it falls quite a bit above ISO 6400, to a minimum of 92.4% at ISO 25,600. The Lumix GH4 pushes dark red and dark blues a fair bit and some other colors slightly, but undersaturates yellow, aqua and cyan. 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 GH4 does reasonably well, producing fairly natural-looking Caucasian skin tones with a slight push towards pink when either Auto or Manual white balance is used, giving a healthy appearance. Darker skin tones have a small nudge towards orange, but overall results are pretty good. 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 GH4 shifts orange toward yellow and cyan toward blue, but most other hue shifts are quite minor. The typical Panasonic yellow to green shift and desaturation is still present, though not as pronounced as some prior Lumix models. The GH4's mean "delta-C" color error after correction for saturation is 5.34 for JPEGs at the base ISO of 200 (100 is an extended ISO). That's about average these days, and color error remains quite stable throughout the ISO range except at the highest ISO setting where it jumps to 6.51. Hue is "what color" the color is.
The Panasonic GH4 lets you adjust image saturation in eleven (!) steps, giving unusually fine control over the effect. The saturation setting also has little effect on contrast, which is good.
|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
Warm colors with Auto and Incandescent white balance setting. Very good color balance with the Manual setting, a little cool with 2,600 Kelvin. Average exposure compensation required.
|Auto White Balance
|Incandescent White Balance
|Manual White Balance
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, though, while the 2,600 Kelvin setting which should match the color temperature of our lights for this shot is a bit too cool with a slight cyan cast. The Panasonic GH4 required +0.3 EV exposure compensation here, about average for this scene. (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.)
Pleasant if slightly cool colors overall, with a tendency toward high contrast under harsh lighting. About average exposure accuracy.
|Auto White Balance,
|Auto White Balance,
Outdoors, the Panasonic GH4 performed well, with good though slightly cool color in the Far-field shot (at right). Skintones are fairly 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 typical for this shot. Despite the bright appearance, few highlights were actually blown in the mannequin's white shirt which is very good, though there are some very deep shadows that are a bit noisy, discolored and posterized. The default exposure is good, just slightly dim for the Far-field shot, but as a result there are very few blown highlights, though again there are some very deep shadows that are somewhat noisy and discolored.
Very high resolution, ~2,450 to ~2,500 lines of strong detail.
|Strong detail to
~2,500 lines horizontal
|Strong detail to
~2,450 lines vertical
|Strong detail to
~2,500 lines horizontal
ACR converted raw
|Strong detail to
~2,450 lines vertical
ACR converted raw
In camera JPEGs, our laboratory resolution chart reveals sharp, distinct line patterns to about 2,500 lines per picture height horizontally, and perhaps a little less in the vertical direction to about about 2,450 lines. Complete extinction of the pattern occurs just after 3,200 lines horizontally and about 3,100 lines vertically. We weren't able to extract significantly more high-contrast resolution by processing the Panasonic GH4'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.
Sharpness & Detail
Fairly conservative default sharpening with just minor edge-enhancement artifacts around high-contrast subjects. Mild to moderate noise suppression visible in the shadows even at base ISO.
|Good definition of high-contrast
elements, with just slightly visible
|Subtle detail: Hair
Noise suppression tends to blur
detail in areas of subtle contrast.
Sharpness. The Panasonic GH4 captures fairly sharp, detailed images overall, with relatively conservative default sharpening. Only minor edge enhancement artifacts are visible on high-contrast subjects such as the sharpening "halos" along the lines and text in the crop above left, so default sharpening here is fairly tame and not overdone, more in keeping with the camera's pro target buyer. 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. Still, this is good noise versus detail processing performance for a 16-megapixel Four Thirds sensor, leaving plenty of detail intact instead of blurring much of it away in an attempt to hide noise. 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 GH4 produces fairly sharp in-camera JPEGs with good detail. As is almost always the case, better 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, we compare an in-camera, best quality JPEG taken at base ISO using default noise reduction and sharpening (on the left) to a matching RAW file converted with Adobe Camera Raw 8.5 using default noise reduction with some strong but tight unsharp masking applied in Photoshop (300%, radius of 0.3 pixels, and a threshold of 0).
As you can see, the in-camera JPEG contains pretty good detail, however ACR extracted additional detail particularly in our troublesome red-leaf swatch. But ACR also revealed more noise, especially in flatter areas (keep in mind base ISO is 200, though). 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 almost always the case shooting in RAW mode provides better detail, color, and control than in-camera JPEGs when converted with a good RAW converter.
ISO & Noise Performance
Good high ISO performance up to ISO 3200.
Default Noise Reduction
|ISO 100||ISO 200||ISO 400|
|ISO 800||ISO 1600||ISO 3200|
|ISO 6400||ISO 12,800||ISO 25,600|
The Panasonic GH4's images are very detailed and clean at ISOs 100 (extended) and 200, with only minor luminance and chrominance noise detectable in the shadows. As ISO increases, noise versus detail also increases as expected, but the trade off remains quite good until ISO 3200 where we start to see noticeable detail loss and more obvious luminance noise, however noise "grain" is fairly fine and tight and image quality is still good. ISO 6400 shows a more abrupt drop in image quality, with some obvious chroma noise as well as luminance noise that starts to take on a crystalline effect. Loss of detail and noise reduction artifacts increase rapidly from there, to the point where the ISO 25,600 setting is very noisy with a peppered look and, while showing strong chroma blotching. Colors also begin to desaturate noticeably above ISO 6400.
Overall, though, high ISO performance is excellent for a Micro Four Thirds model, though as expected, not quite as good as leading 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 with surprisingly good dynamic range. Excellent low-light performance.
|+0.3 EV||+0.7 EV||+1.0 EV|
Sunlight. The Panasonic GH4 did quite well with the deliberately harsh lighting of this test. Contrast is a little high at its default setting as with most cameras, but dynamic range is actually quite good. We felt the +0.7 EV exposure is the best compromise here. Although skintones around the eyes are a bit dark, we prefer it to the +1.0 EV exposure overall, because the latter has a few clipped highlights, though not as many as you might think from the apparent brightness. It's really the photographer's choice here as to which direction to go in. For those Panasonic GH4 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 GH4 performed well with the wide dynamic range of this very harshly lit shot.
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.)
The camera's contrast adjustment was effective in handling the harsh lighting.
|Contrast set to lowest,
|Contrast set to lowest,
The Panasonic GH4's lowest contrast setting did a good job bringing out detail in the shadows and midtones, but had less effect on highlights, however few highlights were clipped to begin with.
|Contrast Adjustment Examples|
Like saturation, the Panasonic GH4 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.
|Tone Curve Adjustment|
|Lower Contrast||Raise Contrast||Brighten Dark Areas|
The Panasonic GH4 also has a curves setting which allows you to adjust the shape of the tone curve to tweak shadows and highlights independently. There are 4 presets (Standard, Raise Contrast, Lower Contrast, and Brighten Dark Areas) as well as 3 custom settings that allow you to adjust the highlight and shadow ends of the curves by +/-5 units. Above are samples using the 3 non-standard presets.
|Aperture Priority, 0 EV, f/8
Face Detection Off
|Aperture Priority, 0 EV, f/8
Face Detection On
|iAuto, 0 EV, f/2.2|
Like most cameras these days, the Panasonic GH4 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 dramatically in both Aperture Priority mode at f/8, and in iAuto mode where the camera had control over aperture.
Panasonic's Intelligent Dynamic Range
The above shots are examples of Panasonic's Intelligent Dynamic Range Control (or iDynamic) 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 iDynamic available on the Panasonic GH4: Low, Standard and High, plus Auto and Off. It's automatically invoked in iAuto and manually selectable in PASM modes. Here, you can see darker midtones and shadows were progressively boosted as the strength was increased, without blowing many highlights in the process.
Far-field HDR Examples
Here, you can see the Panasonic GH4'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. Options include strength settings of Auto +-1EV, +/-2EV or +/-3 EV and whether or not the camera auto aligns the images. Mouse over the links, and click on them the view the full resolution files.
The Auto, +/-1 EV and +/2 EV settings produced very similar exposures, while +/-3 dimmed the entire image. Notice the ghosting of moving objects like the flag, as is expected when compositing multiple images. Also notice the angle of view is narrower in the HDR images, likely because the images have been cropped and upsized during the optional auto alignment process.
Dynamic Range Analysis (RAW mode)
While we once performed our own dynamic range measurements based on in-camera JPEGs as well as converted RAW images (when the camera was supported by Adobe Camera Raw), we've switched to using DxO Labs' results from their DxOMark website. As technology advanced, the dynamic range of modern high-end cameras in some cases exceeded the range of the Stouffer T4110 density scale that we used for our own measurements. DxO's approach based on RAW data before demosaicing is also more revealing, because it measures the fundamental dynamic range of the sensor, irrespective of whatever processing is applied to JPEGs, or to RAW data by off-the-shelf conversion software.
In the following, we use DxO's "Print" dynamic range results, which are scaled based on camera resolution. As the name suggests, this scaling corresponds to the situation in which you print at a given size, regardless of how many megapixels the camera might have. (In other words, if you've decided to make a 13x19 inch print, that's the size you're printing, whether the camera's resolution is 16 or 300 megapixels.) For the technically-minded, you can find a discussion of the reasoning behind this here on the DxOMark website. Also note that DxO Labs uses a signal-to-noise (SNR) threshold of 1 when defining the lower boundary of acceptable luminance noise in their dynamic range measurements, which corresponds to the "Low Quality" threshold of the Imatest software we used to use for this measurement.
In the above graph we compare the Panasonic GH4's normalized dynamic range to its predecessor, the GH3, as well as to the Canon 70D, another interchangeable lens camera that is highly capable when it comes to video (though without 4K support).
As you can see, the GH4's dynamic range (plotted in orange) is just a bit better than the GH3's at the lowest ISO (12.76 vs 12.35 EV), and is among the best we've seen from a Four Thirds sensor, but the two Lumix cameras are essentially equal at ISOs above 200. Note however that the GH4's measured sensor sensitivity is noticeably lower than the GH3's at most ISOs; it's almost a full stop lower than advertised from ISO 200 to 6,400, and it tops out at only ISO 7,533 equivalent (while the GH3 tops out at only ISO 4,832).
The GH4's dynamic range is significantly better than the Canon 70D's at lower ISOs (12.76 vs 11.58 EV at ISO 100) but the 70D catches up at ISO 400, and surpasses the GH4 at higher ISOs. Click here to visit the DxOMark page for the Panasonic GH4 for more of their test results and additional comparisons.
Low Light. The Panasonic Lumix DMC-GH4 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 GH4 should be able to take well-exposed photos in almost any environment in which you can see well enough to walk around in.
Using the default noise reduction setting, noise is fairly well-controlled up to ISO 6400, though turning down NR produced some objectionable chroma noise in darker areas at lower ISOs. (At moderate to high ISOs, even the lowest NR setting eliminates much of it.) We didn't notice any significant issues with hot pixels or heat blooming, and just a hint of pattern noise is visible at the highest ISOs with NR turned down.
Automatic color balance is a little cool particularly at lower light levels, but pretty good.
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 GH4 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 GH4 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 GH4's sensor do better under dim lighting than do the tiny pixels of most point & shoots.
Built-in Flash Test Results
Exposure and Range
A powerful flash for a built-in. Less than average positive exposure compensation required.
|Normal Flash, ISO 200
1/60s, f/4, +0.3 EV
|Slow-Sync Flash, ISO 200
1.6s, f/4, 0 EV
Exposure. Indoors under incandescent background lighting, the Panasonic GH4's flash produced a bright exposure of our Indoor Portrait scene at ISO 200 with +0.3 EV flash exposure compensation. The typical amount required for this shot is +0.7 EV, so the GH4's performance is above average here. The camera's slow-sync flash mode required no compensation for bright results, though the longer exposure resulted in a very warm cast from the ambient background lighting.
|Manufacturer-Specified Flash Range|
Manufacturer-Specified Flash Range Test. Panasonic rates the GH4's flash Guide Number at 12m at ISO 100, or 17m at ISO 200, the same as the GH3's. That works out to about 9.9 feet at f/5.6 and ISO 200, as shot above. As you can see, the Panasonic GH4 captured a bright flash target, so the built-in flash performs to specification. Our standard test method for flash range uses either a fixed setting of ISO 200, to provide a fair basis of comparison between cameras. We've now also begun shooting two shots using the manufacturer-specified camera settings, at the range the company claims for the camera (at Auto ISO if so specified), to assess the validity of the specific claims.
Print Quality: Overall, very good 24 x 36 inch prints at ISOs 100 and 200; ISO 1600 capable of a nice 13 x 19; ISO 6400 prints a good 5 x 7.
ISO 100 and 200 images are excellent at 24 x 36 inches, with nice detail. Colors are generally accurate, but yellows are desaturated and shifted a bit toward green. Despite the extended ISO of 100, prints at both 100 and 200 look practically identical. Even though the GH4 has "only" a 16MP sensor, up to 36 x 48 inch prints are easily 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 in the shadow areas. Colors still look accurate, and the camera still has the ability to resolve fine detail.
ISO 1600 is capable of a good 13 x 19 inch print, with 11 x 14s looking even better. Typical troublesome areas like the red swatch in our test target still looks great at this ISO.
ISO 3200 prints are good at 11 x 14 inches, with some minor grain in the shadows. Also, the red fabric swatch is starting to lose detail. Colors are beginning to be slightly muted as well, but enough saturation is preserved for good prints.
ISO 6400 produces a nice 5 x 7, with 8 x 10s being suitable for less critical applications. Noise is starting to show up more, but is still mostly concentrated in shadowy areas.
ISO 12,800 prints are acceptable at 4 x 6, although colors look slightly muted, but enough color is preserved for decent prints. Noise is quite high here, preventing us from calling any larger size acceptable.
ISO 25,600 does not print a usable 4 x 6 and is best avoided.
While the Panasonic GH4 certainly brings lots of upgrades in terms of video capabilities, it's not altogether much different from the GH3 in terms of still image quality. Housing a similar 16MP sensor, the GH4 yields high quality 24 x 36 inch prints at extended ISO 100 and base ISO 200. This quality is maintained nicely at ISO 800 with relatively large prints for its Four Thirds sensor size, and allows for good 11 x 14 prints up to ISO 3200. The default level of noise reduction does well at these relatively high ISOs to keep noise under control while maintaining a lot of fine detail. At very high ISO levels, however, prints sizes can only go so large before noise takes its toll on fine detail and color.
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.)
The images above were taken from our standardized test shots. For a collection of more pictorial photos, see our Panasonic Lumix DMC-GH4 Photo Gallery .
Not sure which camera to buy? Let your eyes be the ultimate judge! Visit our Comparometer(tm) to compare images from the Panasonic Lumix DMC-GH4 with those from other cameras you may be considering. The proof is in the pictures, so let your own eyes decide which you like best!
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