Panasonic GM1 Exposure

Saturation & Hue Accuracy
Typical mean saturation levels, with about average hue accuracy.

Saturation. The Panasonic GM1 produces images with typical mean saturation levels compared to most cameras at default settings. Mean saturation is 109% (9% oversaturated) at the base ISO of 200, which falls to a minimum of 104.6% at ISO 6400. The Lumix GM1 pushes dark red and dark blues a fair bit 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 GM1 does fairly well, producing 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 GM1 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 GM1's mean "delta-C" color error after correction for saturation is 5.68 for JPEGs at the base ISO of 200 (125 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.

Saturation Adjustment
The Panasonic GM1 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 very slight bluish cast. The Panasonic GM1 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
Good colors overall, with a tendency toward high contrast under harsh lighting. About average exposure accuracy.

Outdoors, the Panasonic GM1 performed well, with good though slightly cool color in the Far-field shot. 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 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
See thumbnails of all test and gallery images

Resolution
Very high resolution, ~ 2,300 to ~2,400 lines of strong detail.

In camera JPEGs, our laboratory resolution chart reveals sharp, distinct line patterns to about 2,400 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 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 GM1'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. Mild to moderate noise suppression visible in the shadows even at base ISO.

Sharpness. The Panasonic GM1 captures sharp, detailed images overall. Some 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 GM1 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.

Electronic Shutter Artifacts. As mentioned in our review, the Panasonic GM1 uses an all-electronic shutter at shutter speeds above 1/500s. This can lead to some artifacts that aren't usually issues when using a mechanical shutter.

Artificial Light Banding. For example, here you can see horizontal banding in a studio shot lit by HMI (Hydrargyrum Medium-arc Iodide) lighting which like many types of artificial lighting, actually pulses but at a rate and duty cycle that is imperceptible humans (when used with electronic ballasts like ours). The image on the right is a highly saturated version of the one on the left to make the banding more obvious, but you can still see the effect in the unmodified version (click on the left image to access the full resolution version). This happens because the light is actually pulsing while sensor data is captured row-by-row from top to bottom at a rate much slower than a mechanical shutter would have travelled at the same shutter speed. (Note that each row is allowed to accumulate charge for 1/1000s in this case, but processing all of them in sequence takes much longer.) This phenomenon only occurs with artificial lighting (such as LED or fluorescent), and will vary with the type, frequency and duty cycle.

Rolling Shutter. For the same reason (capturing and reading sensor data out row-by-row during exposure instead of after a mechanical shutter has ended the exposure), the GM1 is more susceptible to rolling shutter artifacts with moving subjects. You can see an example of this in this crop of one of our gallery shots above, where trees and a fence post which are perpendicular to the ground and the top rail are slanted because the camera was panned from right to left during the exposure. Rolling shutter artifacts are quite common during movie capture because an electronic shutter is always employed then, but be aware this is now an issue with still images at shutter speeds above 1/500s, or when you choose to use electronic only shutter. (Note: Mechanical shutters can also generate some rolling shutter effect because they too expose the sensor with a moving slit at higher shutter speeds, but that slit usually travels down the sensor faster than the GM1's electronic shutter.)

Streaking. We've also noticed some streaking at the higher ISOs (6400 to 25,600) with subject matter containing sudden transitions between dark and light areas, likely also due to the electronic shutter because they didn't occur at shutter speeds below 1/500s and did not occur with the GX7 using its mechanical shutter under identical conditions. The camera's JPEG engine at default noise reduction does a fairly good job at masking them at ISOs below 25,600 as the streaking is more noticeable in RAW files without NR applied (second set of crops).

Note, though, that most of these issues are fairly minor. The banding only happens in artificial light where you're likely to use slower shutters speeds (and thus the mechanical second curtain); rolling shutter only occurs with a rapidly moving camera or subject; and the streaking only occurs at the highest ISOs which we don't recommend using and when you're likely to shoot at slower shutter speeds anyway. Probably the biggest limitation (for flash shooters anyway) is the slow 1/50s flash synchronization speed, however the pop-up flash isn't very powerful anyway and external flash is not even supported. Still, we thought it important to show the consequences of one of the tradeoffs made to achieve the GM1's tiny form-factor. On the plus side, shutter shock (blurring caused by shutter-induced vibrations) is not an issue with an all-electronic shutter, and shutter speeds as high as 1/16,000s are possible with the GM1.

RAW vs In-Camera JPEGs
As noted above, the Panasonic GM1 produces 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 8.3 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, but also shows more noise, especially in areas with little 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
Excellent high ISO performance for a Micro Four Thirds model.

The Panasonic GM1's images are very detailed and clean at ISOs 125 (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, though, high ISO performance is excellent for a Micro Four Thirds model, and quite similar to its big brother, the GX7. 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 good dynamic range. Very good low-light performance.

Sunlight. The Panasonic GM1 did 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 GM1 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 GM1 performed fairly well with the wide dynamic range of this shot, with perhaps just slightly noisier shadows than the GX7.

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

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

The Panasonic GM1'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. (There were few highlights clipped to begin with.) Overall, pretty good performance.

Like saturation, the Panasonic GM1 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 GM1 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 both Aperture Priority at f/8, and in iAuto mode where the camera had control over aperture, and 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 GM1: 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. In this case, Auto had little effect.

HDR mode
Here, you can see the Panasonic GM1'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.

We liked Auto and +/-1 EV the best for this scene, as higher settings didn't work very well with +/-2 making little difference and +/-3 dimming the entire image. Notice the double images and ghosting of objects 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.

As you can see from the above graph comparing the Panasonic GM1's normalized dynamic range to two other Micro Four Thirds models (click for a larger image), the GM1's dynamic range (plotted in orange) isn't quite as good as its big brother, the GX7 (red). That's interesting, given they share the same sensor. Nor is the GM1's dynamic range as good as another compact Micro Four Thirds model, the Olympus E-PM2 (yellow). The GM1's maximum normalized dynamic range at the camera's minimum ISO setting of 125 is about 11.7 EV, which falls to a minimum of 5.8 EV at the maximum setting of ISO 25,600. At low to moderate ISOs, the ~0.5 EV difference in dynamic range may just barely be detectable in real-world images (likely as slightly higher noise in shadows), however at ISOs above 800 the difference is so minor that we doubt it would discernible. Click here to visit the DxOMark page for the Panasonic GM1 for more of their test results and additional comparisons.

Low Light. The Panasonic Lumix DMC-GM1 performed fairly 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 GM1 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 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 heat blooming, but there are some bright pixels that are slightly visible at low ISOs and longer shutter speeds even with long exposure noise reduction enabled, as well as a hint of pattern noise visible at the highest ISOs with NR turned down.

Automatic color balance is 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 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 GM1 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.

The Panasonic GM1 features a new Handheld Night Shot mode which captures and merges six high-ISO images taken in a high-speed burst into a single exposure with reduced noise. This allows usable photos to be taken in low light without a tripod, and the GM1 is the first Panasonic Micro Four Thirds camera to support such a mode. See the Field Test for how well it worked including sample images.

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 GM1 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 GM1's sensor do better under dim lighting than do the tiny pixels of most point & shoots.

Very good 24 x 36 inch prints at ISO 125/200; a nice 13 x 19 at ISO 1600; a good 4 x 6 at ISO 12,800.

ISO 125/200 prints are quite good at 24 x 36 inches, with nice detail and rich colors. Wall display prints are possible up to 30 x 40 inches.

ISO 400 shots look very good at 20 x 30 inches, retaining good detail throughout our test image.

ISO 800 prints are good at 16 x 20 inches. Typical softening in the red channel begins to occur here, as is the case for many cameras we test.

ISO 1600 makes a nice 13 x 19 inch print, with only mild softening in the red fabric and minor noise in flatter areas.

ISO 3200 tends to be the turning point for many Micro Four Thirds cameras, as is the case here, and requires a reduction to 8 x 10 inches due mostly to noise in flatter areas.

ISO 6400 prints a very good 5 x 7. 8 x 10s don't quite pass our official "good" standard, but are not bad for less critical applications.

ISO 12,800 yields a good 4 x 6 for this ISO and sensor type.

ISO 25,600 prints are not usable by our standards; this setting is best avoided entirely.

The Panasonic GM1 turns in a solid performance in the print quality department, and as expected, it yields prints similar to its acclaimed cousin the GX7, which shares the same sensor and processor. These sizes are what we have come to expect from good Micro Four Thirds cameras, and the GM1 certainly doesn't disappoint. Note that the biggest decrease in quality occurs at ISO 3200, so it is best to stay at ISO 1600 and lower if you want to print photos larger than 8 x 10 inches. For online use or small prints, feel free to snap away at ISO 12,800!

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.)