Panasonic GX850 Image Quality


Color

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

ISO Sensitivity
100
200
400
800
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 GX850 produces images with typical saturation levels at default settings. Mean saturation is 111.6% (11.6% oversaturated) at the base ISO of 200 (100 is an extended ISO), which gradually falls to a minimum of 104.4% at ISO 25,600. The Lumix GX850 pushes dark reds and dark blues by quite a bit and some other colors slightly, but undersaturates yellow moderately, and aqua and cyan slightly. 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 GX850 did fairly well, producing natural-looking Caucasian skin tones with a slight push towards pink when Manual white balance was 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 GX850 shifts orange toward yellow, yellow toward green, and cyan toward blue, but most other hue shifts are quite minor. The yellow to green shift along with the desaturation can unfortunately produce some dingy-looking yellows as we've seen from some prior Lumix models. The GX850's mean "delta-C" color error after correction for saturation is 4.75 for JPEGs at the base ISO of 200. That's close to average these days, and color error remains quite stable throughout the ISO range. Hue is "what color" the color is.

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

Sensor

Exposure and White Balance

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

Auto White Balance
+0.3 EV
Incandescent White Balance
+0.3 EV
Manual White Balance
+0.3 EV

Indoors, under normal incandescent lighting, color balance is a little warm and reddish with the Auto white balance setting, but results here are actually better then most. Results with the Incandescent setting are warmer, with a stronger orange-yellow cast. The Manual setting produced fairly accurate results, just slightly warm. The Panasonic GX850 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-looking colors overall, with a tendency toward high contrast under harsh lighting. Above average exposure accuracy.

Manual White Balance,
+0.3 EV
Auto White Balance,
Auto Exposure

Outdoors, the Panasonic GX850 performed well, with natural-looking colors in the Far-field shot. Skin tones are fairly realistic in our "Sunlit" Portrait shot, with a healthy-looking push of pinks and reds when Manual white balance was used, which is preferable to too flat or yellow. Auto white balance was similar. Exposure accuracy was above average, as the camera required only +0.3 EV compensation for our "Sunlit" Portrait shot to keep facial tones reasonably bright. +0.7 EV is 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 fairly clean, but discolored and posterized. The default exposure is quite good for the Far-field shot, resulting in very few blown highlights, though again there are some very deep shadows that are discolored 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
~2,350 to ~2,450 lines of strong detail.

Strong detail to
~2,450 lines horizontal
Camera JPEG
Strong detail to
~2,350 lines vertical
Camera JPEG
Strong detail to
~2,450 lines horizontal
ACR converted raw
Strong detail to
~2,350 lines vertical
ACR converted raw

An in-camera best quality JPEG of our laboratory resolution chart reveals sharp, distinct line patterns up 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 start to interfere and lines begin to merge at these limits.) Complete extinction of the pattern occurs between 3,300 lines and 3,300 lines. We weren't able to extract significantly more high-contrast resolution by processing the Panasonic GX850's RW2 file using Adobe Camera Raw, and the ACR conversion also shows much more 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, though with visible edge-enhancement artifacts on high-contrast subjects. Mild to moderate noise suppression visible in the shadows even at base ISO.

Very good definition of high-contrast
elements, but with visible
sharpening artifacts.
Subtle detail: Hair
Noise suppression tends to blur
detail in areas of subtle contrast.

Sharpness. The Panasonic GX850 captures sharp, detailed images, thanks in part to the lack of an optical low-pass filter, however aliasing artifacts are visible in the form of "jaggies" and subtle moiré patterns. Edge enhancement artifacts are also visible around high-contrast subjects such as the sharpening "halos" along the lines and around the text in the crop above left, but default sharpening 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, although chroma noise is well-controlled. This is good noise versus detail processing performance for a 16-megapixel Micro Four Thirds model, leaving lots of fine detail intact instead of blurring much of it away in an attempt to hide noise, though again some aliasing artifacts are visible. 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 GX850 produces sharp in-camera JPEGs with pretty good detail. As is almost always the case, better detail can be obtained from carefully processing RAW files, with fewer sharpening artifacts to boot. Take a look below to see what we mean:

Base ISO (200)
Camera JPEG, defaults
RAW via Adobe Camera Raw

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 9.6 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 very good detail, however ACR extracted additional detail, particularly in the red-leaf fabric where it managed to resolve some of the fine thread pattern. The ACR conversion however shows much more luminance noise after sharpening, especially 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, 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
Great high ISO performance for a Micro Four Thirds model.

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 GX850's images are very detailed and clean at ISOs 100 (extended) and 200, with only minor luminance noise detectable in the shadows. ISO 400 is also quite detailed, though a touch more noise and blurring from noise reduction can be seen. ISO 800 shows stronger noise reduction, blurring some very fine detail in the process, though overall detail remains very good and chroma noise is low. ISO 1600 is of course a little noisier, but fine detail is still pretty good and chroma noise is still well-controlled, however the GX850's area-specific noise reduction is starting to leave some edges a bit rough and noisy. ISO 3200 shows a larger drop in image quality with more noise reduction artifacts, though there is some fine detail left. At ISO 6400, a crystalline effect starts to appear caused by rectilinear noise reduction artifacts, chroma noise in the form of subtle purple and yellow blotches starts to become visible, and a lot of fine detail is blurred away. Image quality drops off quickly at ISO 12,800 and above, with strong luminance noise and chroma blotching leaving little fine detail intact. Still, a nice improvement over its predecessor, the GF7, across the entire ISO range.

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.

Note that we now shoot this series at f/8 instead of f/4, for increased depth of field (at f/4, it was very difficult to focus for maximum sharpness in the crop area while maintaining consistent focus between models).

Extremes: Sunlit, dynamic range and low light tests
Somewhat high default contrast but with decent dynamic range. Excellent low-light performance, able to capture images and autofocus in very low light.

0 EV +0.3 EV +0.7 EV

Sunlight. The Panasonic GX850 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 +0.3 EV exposure is the best compromise here. Although skin tones around the eyes are a bit dark, we prefer it to the +0.7 EV exposure overall, because there were quite a few clipped highlights at +0.7. It's really the photographer's choice here as to which direction to go in. For those Panasonic GX850 owners that are going to want to just print an image with little or no tweaking, the +0.7 EV image would probably produce a better-looking face uncorrected. The bottom line though, is that the Panasonic GX850 performed fairly well with the wide dynamic range of this shot, though not as good as some competitors. See below for how the Panasonic GX850'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
Aperture Priority, 0 EV, f/8
Face Detection Off
Aperture Priority, 0 EV, f/8
Face Detection On
iAuto, 0 EV, f/2.5

Face Detection. Like most cameras these days, the Panasonic GX850 has the ability to detect faces (up to 15 in a scene), and adjust exposure and focus accordingly. Oddly, as you can see from the examples above, face detection didn't improve exposure in Aperture Priority at f/8 even though EXIF indicates a face was detected, however in iAuto mode where the camera had control over aperture it produced a much brighter image at f/2.5, and automatically applied Intelligent D-Range (see below).


Far-field Intelligent D-Range Examples
Off
Low

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 GX850: Low, Standard and High, plus Auto and Off. It's automatically invoked in iAuto and some scene modes and manually selectable in PASM modes. Above, you can see darker midtones and shadows were progressively boosted as the strength was increased, while brighter areas were reduced.


Far-field HDR Examples
Off

HDR mode
Here, you can see the Panasonic GX850'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 pretty good job here, producing results similar to +/-1 EV which was arguably the best for this scene, while +/-3 dimmed the entire image. Notice the double images and ghosting of some branches, the flag or people moving between frames. Also notice the angle of view is narrower in the HDR images, 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.

Here we compare the Panasonic GX850's (GX800 in Europe) dynamic range (in orange) to its closest predecessor's, the GM1 (yellow), as DxOMark has not tested the GF7 as of this writing. Also compared is the Olympus E-PL7, another compact and affordable 16-megapixel Micro Four Thirds camera that directly competes with the GX850. (DxOMark has not tested the E-PL8 or E-PL9 yet either.)

As you can see from the above graphs, the GX850's dynamic range is noticeably improved over the GM1's at low to moderate ISOs. The GX850 has its peak dynamic range at its extended low ISO setting of 100, measured at about 13.3 EV versus the GM1's 11.7 EV at ISO 125. The advantage narrows as sensitivity increases, but the GX850 only falls to the same levels as the GM1 above around ISO 1600.

The GX850 performed very similar to the E-PL7 in terms of dynamic range within its native ISO range, as they likely use similar or identical sensors, however the GX850 managed almost a stop better at its extended low ISO 100 setting while the E-PL7's dynamic range remained the same at its extended low ISO 100 setting as its native base ISO of 200. The slight differences at higher ISOs would be difficult to detect in real-world shots.

Assuming the GM1's dynamic range is similar to the GF7's, we can see that dynamic range has improved significantly over its predecessor at low to moderate ISOs, and is very similar to a direct competitor's at non-extended ISOs.

Click here to visit the DxOMark page for the Panasonic GX850 for more of their test results and additional comparisons.


  1 fc
11 lux
1/16 fc
0.67 lux
1/16 fc
No NR
ISO
200

1s, f2.8

15s, f2.8

15s, f2.8
ISO
3200

1/15s, f2.8

1s, f2.8

1s, f2.8
ISO
25600

1/125s, f2.8

1/8s, 1 f2.8

1/8s, f2.8

Low Light. The Panasonic Lumix DMC-GX850 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 GX850 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 with a very fine, tight noise "grain", though as you'd expect, noise is quite high at the maximum ISO of 25,600 which should probably be avoided except in emergencies.

We didn't notice any significant issues with hot pixels, though with long exposure noise reduction turned off (rightmost column) there are a lot of slightly brighter pixels in the shadows at ISO 200, as well as a few hot pixels. We didn't detect any issues with heat blooming or fixed pattern noise, but be aware that the maximum exposure supported by the GX850 is 60 seconds, which doesn't make it a good camera for long exposures.

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

Low-light AF: The camera's autofocus system was able to focus our low-contrast AF target down to -4.3 EV, and on our newer high-contrast target down to -4.4 EV unassisted with an f/2.8 lens. That's very good for its class, and slightly exceeds Panasonic's -4 EV spec. The Panasonic GX850 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 GX850 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 GX850's sensor do better under dim lighting than do the tiny pixels of most point & shoots.

Output Quality

Print Quality

Very good 24 x 36 inch prints up to ISO 400; Good 16 x 20 inch print at ISO 800; and a nice 8 x 10 at ISO 3200.

ISO 100 and 200 prints are very good at 24 x 36 inches, displaying rich color, superb fine detail, and a nice three-dimensional pop to the images. The 30 x 40 inch prints will certainly work for wall-display purposes, but the 16-megapixel resolution limits the closeness of the viewing distance.

ISO 400 images are also quite good at 24 x 36 inches. There is just a trace of mild softening in areas of fine detail, but not enough to keep us from awarding our good overall seal to this size, and there's no noise apparent anywhere.

ISO 800 produces 20 x 30 inch prints that come very close to passing our good seal, and can certainly be used for less critical applications or most wall display purposes. The 16 x 20 inch prints here tighten up quite nicely, and display very good fine detail and excellent colors, with only a mild softening in the red channel, which is typical of most crop sensor cameras at this ISO and higher.

ISO 1600 yields a 16 x 20 inch print that may pass the grade for less critical printing applications, but for ensuring a good print we recommend the 13 x 19 inch size and lower at this gain setting. With only a mild trace of noise in flatter areas of our target and just a touch of softness in the red channel, these are still very good prints.

ISO 3200 delivers an 11 x 14 inch print that just passes our good seal of approval. There is mild noise apparent in flatter areas of our Still Life target, and most all contrast detail is now lost in our tricky red-leaf fabric swatch, but it's still a print that merits our overall good seal. For most critical printing needs, though, we suggest limiting size to an 8 x 10 here.

ISO 6400 outputs an 8 x 10 inch print that's really not bad given the "gain strain" at this setting on a Four-Thirds sensor, but we recommend printing at that size for less critical applications only. If you must push the camera to this gain setting for prints, we recommend 5 x 7's as the maximum size here.

ISO 12,800 yields a 5 x 7 inch print similar to the 8 x 10 above, and will likely be fine for less critical printing purposes. But for a good print we suggest sticking with 4 x 6 inch prints here, which still yield a lot of color and detail for such a high ISO.

ISO 25,600 surprisingly delivers a 4 x 6 inch print that's not too bad! You can get away with it for anything not too important, but otherwise we recommend avoiding this ISO for prints.

The Panasonic GX850 turned in a solid performance in the print quality department, especially given its class and sensor resolution. You're in really good hands up to ISO 1600, with tons of fine detail and excellent colors throughout. Panasonic is one of the few manufacturers that manages to keep colors from muting too badly as ISO rises, and GX850 owners will benefit from this as ISO rises. By ISO 6400 the gain really starts to strain the GX850, so if you can remain at ISO 3200 and below your prints will reap the rewards. Well done to Panasonic on this camera for really good image quality for the price.

About our print-quality testing: Our "Reference Printer"

Testing hundreds of digital cameras, we've found that you can only tell 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 routinely print sample images from the cameras we test on our Canon imagePROGRAF PRO-1000 printer, which we named our "Printer of the Year" in our 2015 COTY awards.

The Canon PRO-1000 has a lot of characteristics that make it a natural to use for our "reference printer." When it comes to judging how well a camera's photos print, resolution and precise rendering are paramount. The PRO-1000's more than 18,000 individual nozzles combine with an air feeding system that provides exceptional droplet-placement accuracy. Its 11-color LUCIA PRO ink system delivers a wide color gamut and dense blacks, giving us a true sense of the cameras' image quality. To best see fine details, we've always printed on glossy paper, so the PRO-1000's "Chroma Optimizer" overcoat that minimizes "bronzing" or gloss differential is important to us. (Prior to the PRO-1000, we've always used dye-based printers, in part to avoid the bronzing problems with pigment-based inks.) Finally, we just don't have time to deal with clogged inkjet heads, and the PRO-1000 does better in that respect than any printer we've ever used. If you don't run them every day or two, inkjet printers tend to clog. Canon's thermal-inkjet technology is inherently less clog-prone than other approaches, but the PRO-1000 takes this a step further, with sensors that monitor every inkjet nozzle. If one clogs, it will assign another to take over its duties. In exchange for a tiny amount of print speed, this lets you defer cleaning cycles, which translates into significant ink savings. In our normal workflow, we'll often crank out a hundred or more letter-size prints in a session, but then leave the printer to sit for anywhere from days to weeks before the next camera comes along. In over a year of use, we've never had to run a nozzle-cleaning cycle on our PRO-1000.

See our Canon PRO-1000 review for a full overview of the printer from the viewpoint of a fine-art photographer.

*Disclosure: Canon provided us with the PRO-1000 and a supply of ink to use in our testing, and we receive advertising consideration for including this mention when we talk about camera print quality. Our decision to use the PRO-1000 was driven by the printer itself, though, prior to any discussion with Canon on the topic. (We'd actually been using an old Pixma PRO 9500II dye-based printer for years previously, and paying for our own ink, until we decided that the PRO-1000 was the next-generation printer we'd been waiting for.)

 

The images above were taken from our standardized test shots. For a collection of more pictorial photos, see our Panasonic Lumix DC-GX850 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 DC-GX850 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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