Panasonic GF7 Exposure

Saturation & Hue Accuracy
Slightly lower than average mean saturation levels, with about average hue accuracy.

Saturation. The Panasonic GF7 produces images with slightly muted colors compared to most cameras at default settings. Mean saturation is 107.2% (7.2% oversaturated) at the base ISO of 200, which falls to a minimum of 100.5% at ISO 25600. The Lumix GF7 pushes dark red and dark blues moderately and some other colors slightly, but undersaturates yellow, light green, 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 GF7 does fairly well, producing reasonably 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 GF7 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 GF7's mean "delta-C" color error after correction for saturation is 5.11 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. Hue is "what color" the color is.

Exposure and White Balance

Indoors, incandescent lighting
Warm colors with Auto and Incandescent white balance setting. Good color balance with the Manual setting. Average positive exposure compensation required.

Indoors, under normal incandescent lighting, color balance is warm with the Auto white balance setting. Results with the Incandescent setting are also too warm, with a slightly stronger orange-yellow cast. The Manual setting produced accurate results, just a hair on the cool side. The Panasonic GF7 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
Natural colors overall, with a tendency toward high contrast under harsh lighting. About average exposure accuracy.

Outdoors, the Panasonic GF7 performed well, with natural-looking though slightly cool color in the Far-field shot. Skin tones 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, only a few highlights were actually blown in the mannequin's white shirt which is quite good, though there are some very deep shadows that are a bit noisy 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 a bit noisy and posterized. Default contrast is on the high side, but that's how most consumers prefer their photos.

See full set of test images with explanations
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Resolution
~ 2,350 to ~2,450 lines of strong detail.

In camera JPEGs, our laboratory resolution chart reveals sharp, distinct line patterns to about 2,450 lines per picture height horizontally, and about 2,350 lines in the vertical direction. (Some might argue for higher, but aliasing artifacts begin to interfere at these limits.) Complete extinction of the pattern occurs just after 3,000 lines horizontally and about 2,800 vertically. We weren't able to extract significantly more high-contrast resolution by processing the Panasonic GF7'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
Good sharpness overall, with minor edge-enhancement artifacts on high-contrast subjects. Mild to moderate noise suppression visible in the shadows even at base ISO.

Sharpness. The Panasonic GF7 captures reasonably sharp images overall. Some fairly 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, but default sharpening here is fairly typical for consumer-oriented models, and not too overdone. 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. The GF7 also leaves behind a little more chroma noise than some other brands. Still, this is good noise versus detail processing performance for a 16-megapixel Micro Four Thirds model, 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 GF7 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 JPEG taken at base ISO using default noise reduction and sharpening (on the left) to a matching RAW file converted with Adobe Camera Raw 9.0 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 the red-leaf fabric where it managed to resolve some of the thread pattern. The ACR conversion also shows less chroma noise at default settings, though it shows more luminance noise after sharpening, especially in areas with flat detail. 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
Good high ISO performance for a Micro Four Thirds model.

The Panasonic GF7's images are detailed and clean at ISOs 100 (extended) and 200, with only minor luminance and chrominance noise detectable in the shadows. ISO 400 is also quite detailed, though a touch more noise can be seen. ISO 800 shows stronger noise reduction blurring some very fine detail in the process, though overall detail remains very good. ISO 1600 is of course a little noisier, but fine detail 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 bit of a crystalline peppered effect at ISO 3200. At ISO 6400 and above, the crystalline effect becomes progressively stronger while fine detail is reduced to the point where very little fine detail is left in the hair at ISO 25,600. Chroma noise also becomes progressively stronger and objectionable at ISO 6400 and above.

Overall, high ISO performance is quite similar to recent Panasonic Micro Four Thirds models, as expected, which is to say pretty good. 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 decent dynamic range. Very good low-light performance.

Sunlight. The Panasonic GF7 did fairly well with the deliberately harsh lighting of this test. Contrast is a little high at its default setting, but dynamic range is decent in JPEGs. 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 fewer clipped highlights. It's really the photographer's choice here as to which direction to go in. For those Panasonic GF7 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 GF7 performed fairly well with the wide dynamic range of this shot, though not as good as some competitors. See below for how the Panasonic GF7's sensor performs (RAW mode) in terms of dynamic range.

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.)

Face Detection. Like most cameras these days, the Panasonic GF7 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 made a huge difference to exposure in Aperture Priority mode at f/8. iAuto mode where the camera had control over aperture was also improved, but not as much. It also automatically applied Intelligent D-Range (see below).

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 GF7: Low, Standard and High, plus Auto and Off. It's automatically invoked in iAuto and some scene modes 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. As a result, though, noise is more visible, especially noticeably in areas with little detail such as the sky.

HDR mode
Here, you can see the Panasonic GF7'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.

Auto did a decent job, producing results similar to +/-1 EV, while +/-3 dimmed the entire image. Notice the double images and ghosting of the flag or people moving between frames. 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.

Sorry, DxOMark has not tested the GF7 at timing of writing. We'll to come back and fill this section in after they do.

Low Light. The Panasonic Lumix DMC-GF7 performed well in our low light tests, able to capture bright images down to the lowest light level we test at. The darkest level equates to about 1/16 the brightness of average city street lighting at night, so the Panasonic GF7 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 low at ISO 200 and well-controlled at ISO 3200, though as you'd expect, noise is quite high at the maximum ISO of 25,600. We didn't notice any significant issues with hot pixels, though with long exposure noise reduction turned off (rightmost column) there were a lot of slightly brighter pixels in the shadows at base ISO. We didn't detect any issues with heat blooming or pattern noise.

Automatic color balance is just a touch cool particularly at lower light levels, but pretty neutral.

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 GF7 also has a focus-assist light 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 GF7 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 GF7's sensor do better under dim lighting than do the tiny pixels of most point & shoots.

Print Quality
Very nice 24 x 36 inch prints at ISO 100/200; a good 8 x 10 inch print at ISO 3200; a quite usable 4 x 6 at ISO 12,800.

ISO 100 and 200 prints look practically identical to each other, and both ISOs print very nicely up to 24 x 36 inches. You can see very minor softness and extremely subtle pixelation if you look closely, but at typical viewing distances for prints of this size, they look very good with lots of detail and bright colors.

ISO 400 images look very similar to the previous ISOs, but with just the slightest hint of softness compared to ISO 200. That being said, we don't feel this impacts the print size at this sensitivity, and we're comfortable calling it at 20 x 30 inches here, as well.

ISO 800 prints top out at 16 x 20 inches. At this ISO sensitivity, images are now showing a bit more softness due to noise, but it's all very well controlled. Colors are still bright and pleasing, but lower contrast areas like our tricky red-leaf fabric are showing a drop in detail, for example.

ISO 1600 images show a further decrease in fine detail, making 11 x 14 inches the largest we're really comfortable with recommending. However, a 13 x 19 inch print could work for less critical applications.

ISO 3200 prints could perhaps work at 11 x 14 inches for less crucial shots, but the subtle increase in noise makes an 8 x 10 inch print the size we're calling for this sensitivity.

ISO 6400 images make for a nice 5 x 7 inch print. An 8 x 10 is a risky proposition, but it's not too bad -- just a bit too soft for our tastes. At 5 x 7 inches, detail and colors are quite nice at this ISO.

ISO 12,800 prints max out at 4 x 6 inches. Impressive for such a small camera, and noise appears well controlled at this print size, but any larger and it's a bit too noisy and soft.

ISO 25,600 images are too soft and noisy for our liking and should be avoided for prints.

Like its GM5 and GX7 cousins, the 16-megapixel Panasonic GF7 performs well in our print quality testing for a Micro Four Thirds model. The camera manages to impress with large, nicely detailed prints all the way up to 24 x 36 inches at ISOs 100 and 200, though they are just a touch soft. Towards the mid-range of ISOs, the GF7 manages to keep noise very well controlled, offering a nice 11 x 14 inch print at ISO 1600 or a solid 8 x 10 at ISO 3200. At the top end of the ISO scale, the GF7 manages to squeak out a usable 4 x 6 at ISO 12,800, but we'd recommend avoiding ISO 25,600 entirely for prints.

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.)