Panasonic GX9 Exposure

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

Saturation. The Panasonic GX9 produced a default mean saturation of about 109.8% (9.8% oversaturated) at the base ISO of 200, which is typical. The Lumix GX9 pushes dark blues and dark red moderately and some other colors slightly, but undersaturates yellow a bit more than we'd like. Still, overall saturation levels are pleasing. 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. The Panasonic GX9 does fairly well here, producing reasonably natural-looking Caucasian skin tones with a slight boost to pinks with either Auto or Manual white balance in simulated daylight. 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 GX9 shifts orange toward yellow moderately and yellow toward green mildly, while cyan is shifted toward blue by quite a bit (for better-looking skies), but most other hue shifts are quite minor. The typical Panasonic yellow to green shift and desaturation still exists producing slightly dingy yellows, but it's not as pronounced as some earlier models. The GX9's mean "delta-C" color error after correction for saturation is 5.6 for JPEGs at the base ISO of 200 (100 is an extended ISO). That's about average hue accuracy these days. Hue is "what color" the color is.

Exposure and White Balance

Indoors, incandescent lighting
Warm color casts with default Auto and Incandescent white balance settings. Very good color balance with the Manual setting. Average positive exposure compensation required.

Indoors, under normal incandescent lighting, color balance is warm with the default Auto white balance (AWB) setting, however when AWBc is selected, colors are more neutral though with a slight magenta tint. Results with the Incandescent setting are much too warm, with a stronger orange-yellow cast. The Manual (Custom) white balance setting produced very neutral results. The Panasonic GX9 required +0.3 EV exposure compensation here, which is 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.

In simulated daylight, the Panasonic GX9 performed quite well. Skin tones are fairly realistic in our "Sunlit" Portrait shot, with a healthy-looking pinkish tint. Exposure accuracy is about average, as the camera required +0.7 EV compensation to keep facial tones reasonably bright. That's typical for this shot. Despite the bright appearance of the mannequin's white shirt, very few highlights are actually blown which is quite good, though there are some very deep shadows that contain very good detail, but are discolored with a green tint.

Resolution
~ 2,700 to 2,750 lines of strong detail.

In a best-quality camera JPEG, our laboratory resolution chart reveals sharp, distinct line patterns to just over 2,700 lines per picture height horizontally, and to about 2,750 lines in the vertical direction. (Some might argue for higher, but lines begin to merge and aliasing artifacts begin to interfere at these limits.) Complete extinction of the pattern occurs between 3,500 and 3,600 lines per picture height in both directions. We weren't able to extract significantly more resolution by processing the Panasonic GX9's RW2 file using Adobe Camera Raw, and the ACR conversion also shows much higher 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
Very good sharpness overall, with only minor edge-enhancement artifacts on high-contrast subjects. Mild to moderate noise suppression visible in the shadows even at base ISO.

Sharpness. The Panasonic GX9 captures sharp, detailed images with a sharp lens. Sharpness appears to be higher than the GX8, thanks to the lack of an anti-aliasing filter (although some of the increase in sharpness in our images is because we switched lenses and reduced aperture from f/8 to f/5.6 since the GX8 was shot). Some minor edge enhancement artifacts are visible on high-contrast subjects such as the sharpening "haloes" along the lines and text in the crop above left, but default sharpening is well judged 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 mannequin's hair, as well as in areas with low local contrast. This is pretty good noise versus detail processing performance for a 20-megapixel Micro Four Thirds model, leaving plenty of detail intact instead of blurring much of it away in an attempt to hide noise. Do however notice the aliasing artifacts and demosaicing errors in the hair. This is unfortunately quite common, especially from cameras without an anti-aliasing filter. 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 GX9 produces sharp in-camera JPEGs with very 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 9.1 via DNG Converter 10.4 using default noise reduction with some fairly 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 very good detail (among the highest we've seen from a MFT camera thus far) with better contrast, however as is usually the case, ACR extracted additional detail, particularly in the red-leaf fabric where it managed to resolve more of the fine thread pattern. However, the ACR conversion also contains much higher luminance noise after sharpening, especially noticeable in flatter 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, while the GX9's JPEG engine does a pretty good job, shooting in raw mode produces better detail and provides more 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 GX9's images are very detailed and clean at ISOs 100 (extended) through 400, with only minor luminance and chrominance noise detectable in the shadows, although as mentioned previously, it is a little prone to aliasing artifacts. ISO 800 shows slightly higher luminance noise and stronger noise reduction, blurring some very fine detail in the process, though overall detail remains quite good. ISO 1600 is of course a little noisier and softer, but fine detail is still very good. ISO 3200 is a bit of a turning point, with stronger blurring and loss of detail from stronger noise reduction, producing a bit of a "crystalline" effect in flatter areas. However chroma noise remains well controlled.. At ISO 6400 and above, the "crystalline" noise reduction artifacts become 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 and blotching also become progressively stronger and objectionable at ISO 6400 and above, and there's a peppered effect at ISO 12,800 and 25,600 from darker pixels as well. There's also a noticeable drop in saturation as well as a color shift at the highest ISOs.

Still, high ISO performance appears to be very good and quite competitive with 20-megapixel 4/3" rivals. 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.

Extremes: Sunlit, dynamic range and low light tests
Somewhat high default contrast but with very good dynamic range. Very good low-light performance.

Sunlight. The Panasonic GX9 performed well with the deliberately harsh lighting of this test. Contrast is a little high at its default setting, but dynamic range is quite good in JPEGs. We felt the +0.7 EV exposure is the best compromise here. Although shadows around the eyes are a bit dark, we prefer it to the +1.0 EV exposure overall, as the latter is a bit too bright, although surprisingly few highlights are blown even at +1.0 EV. It's really the photographer's choice here as to which direction to go in. For those Panasonic GX9 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 GX9 performed well with the wide dynamic range of this shot even without the use of Intelligent D-Range or Highlight/Shadow tweaks (see below), especially for a Four Thirds sensor.

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 GX9 has the ability to detect faces, and adjust exposure and focus accordingly. As you can see from the examples above, it worked well, as the center image with face detection enabled is much better exposed for the face without having to use exposure compensation, though some highlights were blown. The Full Auto setting chose Portrait scene mode which selected a larger aperture (f/1.6) for much less depth-of-field and better subject isolation. It too was much brighter than Aperture Priority without face detection, though again, quite a few highlights are blown.

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 GX9: Low, Standard and High, plus Auto and Off. It's automatically invoked in iAuto and manually selectable in PASM modes. Here, you can see enabling iD-Range made a huge difference to the exposure without requiring any exposure compensation (it appears to use smarter metering and detected a face). Auto did a good job here, and darker midtones and shadows were progressively boosted as the strength was increased, although some highlights were blown in the process. As a result, though, noise is a little more visible, especially noticeably in areas with little detail.

Highlight/Shadow Adjustment
Above, we can see the GX9's preset Highlight and Shadow control options at work on our "Sunlit" Portrait test shots. This feature lets you adjust the tone curve using 4 preset options (Standard, Higher Contrast, Lower Contrast and Brighten Shadows), plus it gives you 3 Custom settings which let you adjust the curve on a grid. This gives you individual control of the highlight, midtone and shadow portions of the tone curve, unlike the regular contrast adjustment. Mouse over the links to load the associated thumbnail, and click on the links to visit the full resolution image. (Apologies for the dim images, we should have applied some positive exposure compensation here.)

HDR mode
Here, you can see the Panasonic GX9's High Dynamic Range mode at work. HDR mode takes three images at different exposures and combines them to increase dynamic range. Four settings are available, ranging from Auto to up to +/-3 EV of exposure difference. Mouse over the links, and click on them the view the full resolution files.

Auto and +/-2 EV produced very similar results, while +/-3 dimmed the entire image, so the feature did not work very well for these shots. (Again, we should have used some positive exposure compensation here.) Be aware that double images and ghosting are possible when elements in the scene move 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.) 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.

Unfortunately, DxOMark has not yet tested the Panasonic GX9 (also known as the GX7 Mark III in Japan) as of this writing, but we'll come back and update this section once they do.

Low-light Autofocus
The GX9's autofocus system was able to focus on our legacy low-contrast AF target down to -3.4 EV unassisted with an f/2.8 lens, and down to -4.2 EV with our newer high-contrast target. This is very good, especially for a camera with contrast-detect autofocus. The Panasonic GX9 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.

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 GX9 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 cameras with phase-detect systems. That said, though, the larger, more sensitive pixels of the GX9's sensor do better under dim lighting than do the tiny pixels of most point & shoots.

Built-in Flash
Decent performance for a tiny pop-up flash.

Exposure. Indoors under incandescent background lighting, the GX9's flash underexposed our standard indoor portrait scene at ISO 200 and f/4, even with +1.0 EV of flash exposure compensation applies. (An average of +0.7 EV is normally needed for this shot.) However with Auto ISO, the camera produced a good flash exposure requiring just +0.3 EV of flash exposure compensation, though the camera boosted ISO to 500. Both images above have a warm, orange cast from the tungsten ambient lighting.

Print Quality
Excellent 30 x 40 inch prints at ISO 100/200; a good 16 x 20 inch print at ISO 1600 and a solid 8 x 10 at ISO 6400.

ISO 100/200 prints are excellent across the board at 30 x 40 inches, delivering rich, vibrant colors and crisp detail throughout. Wall display prints are possible at even larger sizes, depending on your viewing distance, until you run out of available resolution. The prints here at base ISO and extended low from the GX9 are really quite superb and worth printing large!

ISO 400 images are quite good at 24 x 36 inches, displaying crisp fine detail and excellent color reproduction. 30 x 40 inch prints are fine here for wall display purposes and less critical applications as well, but it's best to remain at 24 x 36 inches for your most critical prints.

ISO 800 yields a very good 16 x 20 inch print, with only a minor loss in fine detail crispness and showing very little in the way of apparent noise. The 20 x 30 inch prints here are not bad at all and can definitely be used for less critical applications, though anything higher reveals a bit too much noise in certain areas of the print.

ISO 1600 is also capable of delivering a good print at 16 x 20 inches! This is a nice feat for a Four Thirds sensor system at this ISO. There is a minor trace of chroma noise in flatter areas of our test target, and yet fine detail is still rendered nicely at this size as well as good color reproduction throughout. For the most critical printing at this ISO we recommend a size reduction to 13 x 19 inches, but the 16 x 20 does indeed pass our "good" grade.

ISO 3200 delivers a solid 11 x 14 inch print. There is some obvious softening in the red channel at this point, which is a fairly common theme as ISO rises in modern digital cameras, but noise is well-controlled at this print size overall, and there's still plenty of definition in the finely detailed areas of our Still Life target.

ISO 6400 prints an 8 x 10 image that just passes our good seal of approval, and this is yet again a high bar for a Four Thirds sensor to pull off. All contrast detail is now lost in our tricky target red-leaf swatch, but again this is very common for all but full frame sensors and larger by this ISO. Good color reproduction remains, and generally good fine detail, so we are confident in calling this print size "good."

ISO 12,800 yields a 5 x 7 that almost passes our good grade, and can definitely be used for general purpose printing and less critical applications. For anything important we recommend the 4 x 6 inch prints here.

ISO 25,600 comes close to passing our good grade at 4 x 6 inches, and like the 5 x 7 above can certainly be used for casual printing at this size, but for anything important we recommend shying away from this ISO entirely.

The GX9 continues the excellent tradition of this line from Panasonic in the print quality department, even pushing usable print sizes a notch higher at a few critical ISOs than its (numerical) predecessor, the GX8. Indeed, to be able to produce a good 8 x 10 inch print at ISO 6400 is a nice feat for this sensor size, and we therefore feel confident recommending the Panasonic GX9 for higher-end printing purposes. In addition, everything from ISO 1600 and lower is really quite good, and your prints will thank you for it.