Panasonic GX800 vs Sony A7S III
The Panasonic Lumix DMC-GX800 (called Panasonic GX850 in some regions) and the Sony Alpha 7S III are two digital cameras that were revealed to the public, respectively, in January 2017 and July 2020. Both the GX800 and the A7S III are mirrorless interchangeable lens cameras that are based on a Four Thirds (GX800) and a full frame (A7S III) sensor. The Panasonic has a resolution of 15.8 megapixels, whereas the Sony provides 12 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
Going beyond this snapshot of core features and characteristics, what are the differences between the Panasonic Lumix DMC-GX800 and the Sony Alpha 7S III? Which one should you buy? Read on to find out how these two cameras compare with respect to their body size, their imaging sensors, their shooting features, their input-output connections, and their reception by expert reviewers.
An illustration of the physical size and weight of the Panasonic GX800 and the Sony A7S III is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All size dimensions are rounded to the nearest millimeter.
The GX800 can be obtained in three different colors (black, silver, red), while the A7S III is only available in black.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A7S III is considerably larger (77 percent) than the Panasonic GX800. Moreover, the A7S III is substantially heavier (160 percent) than the GX800. It is noteworthy in this context that the A7S III is splash and dust-proof, while the GX800 does not feature any corresponding weather-sealing.
The above size and weight comparisons are to some extent incomplete since they do not consider the interchangeable lenses that both of these cameras require. A larger imaging sensor will tend to go along with bigger and heavier lenses, although exceptions exist. You can compare the optics available for the two cameras in the Micro Four Thirds Lens Catalog (GX800) and the Sony FE Lens Catalog (A7S III). Mirrorless cameras, such as the two under consideration, have the additional advantage of having a short flange to focal plane distance, which makes it possible to mount many lenses from other systems onto the camera via adapters.
Concerning battery life, the GX800 gets 210 shots out of its DMW-BLH7 battery, while the A7S III can take 600 images on a single charge of its NP-FZ100 power pack. The power pack in the A7S III can be charged via the USB port, which can be very convenient when travelling.
The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. If you would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.
|1.||Panasonic GX800||107 mm||65 mm||33 mm||269 g||210||n||Jan 2017||549|
|2.||Sony A7S III||127 mm||97 mm||81 mm||699 g||600||Y||Jul 2020||3,499|
|3.||Canon M100||108 mm||67 mm||35 mm||302 g||295||n||Aug 2017||499|
|4.||Canon M10||108 mm||67 mm||35 mm||301 g||255||n||Oct 2015||499|
|5.||Panasonic GX80||122 mm||71 mm||44 mm||426 g||290||n||Apr 2016||799|
|6.||Panasonic G7||125 mm||86 mm||77 mm||410 g||350||n||May 2015||649|
|7.||Panasonic GF7||107 mm||65 mm||33 mm||266 g||230||n||Jan 2015||499|
|8.||Panasonic GM5||99 mm||60 mm||36 mm||211 g||220||n||Sep 2014||749|
|9.||Panasonic G6||122 mm||85 mm||71 mm||390 g||340||n||Apr 2013||599|
|10.||Panasonic GF6||111 mm||65 mm||38 mm||323 g||340||n||Apr 2013||499|
|11.||Panasonic GM1||99 mm||55 mm||30 mm||204 g||230||n||Oct 2013||749|
|12.||Panasonic GF5||108 mm||67 mm||37 mm||267 g||360||n||Apr 2012||499|
|13.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|14.||Sony A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|15.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|16.||Sony A7R II||127 mm||96 mm||60 mm||625 g||290||Y||Jun 2015||3,199|
|17.||Sony A7S II||127 mm||96 mm||60 mm||627 g||370||Y||Sep 2015||2,999|
Any camera decision will obviously take relative prices into account. The retail prices at the time of the camera’s release place the model in the market relative to other models in the producer’s line-up and the competition. The GX800 was launched at a markedly lower price (by 84 percent) than the A7S III, which puts it into a different market segment. Usually, retail prices stay at first close to the launch price, but after several months, discounts become available. Later in the product cycle and, in particular, when the replacement model is about to appear, further discounting and stock clearance sales often push the camera price considerably down.
The size of the imaging sensor is a crucial determinant of image quality. A large sensor will generally have larger individual pixels that offer better low-light sensitivity, provide wider dynamic range, and have richer color-depth than smaller pixels in a sensor of the same technological generation. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the background. On the downside, larger sensors tend to be associated with larger, more expensive camera bodies and lenses.
Of the two cameras under consideration, the Panasonic GX800 features a Four Thirds sensor and the Sony A7S III a full frame sensor. The sensor area in the A7S III is 276 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.0. The sensor in the GX800 has a native 4:3 aspect ratio, while the one in the A7S III offers a 3:2 aspect.
Despite having a smaller sensor, the Panasonic GX800 offers a higher resolution of 15.8 megapixels, compared with 12 MP of the Sony A7S III. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.77μm versus 8.40μm for the A7S III). Moreover, it should be noted that the A7S III is much more recent (by 3 years and 6 months) than the GX800, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that the GX800 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Panasonic GX800 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the GX800 for good quality output (200 dots per inch) amounts to 23 x 17.2 inches or 58.3 x 43.8 cm, for very good quality (250 dpi) 18.4 x 13.8 inches or 46.7 x 35 cm, and for excellent quality (300 dpi) 15.3 x 11.5 inches or 38.9 x 29.2 cm. The corresponding values for the Sony A7S III are 21.2 x 14.2 inches or 53.8 x 36 cm for good quality, 17 x 11.3 inches or 43.1 x 28.8 cm for very good quality, and 14.1 x 9.4 inches or 35.9 x 24 cm for excellent quality prints.
The Panasonic Lumix DMC-GX800 has a native sensitivity range from ISO 200 to ISO 25600, which can be extended to ISO 100-25600. The corresponding ISO settings for the Sony Alpha 7S III are ISO 80 to ISO 102400, with the possibility to increase the ISO range to 40-409600.
For many cameras, data on sensor performance has been reported by DXO Mark. This service is based on lab testing and assigns an overall score to each camera sensor, as well as ratings for dynamic range ("DXO Landscape"), color depth ("DXO Portrait"), and low-light sensitivity ("DXO Sports"). Of the two cameras under consideration, the A7S III offers substantially better image quality than the GX800 (overall score 13 points higher). The advantage is based on 0.5 bits higher color depth, 0.6 EV in additional dynamic range, and 2.1 stops in additional low light sensitivity. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
| DXO |
|1.||Panasonic GX800||Four Thirds||15.8||4592||3448||4K/30p||23.2||13.3||586||73|
|2.||Sony A7S III||Full Frame||12.0||4240||2832||4K/120p||23.7||13.9||2520||86|
|5.||Panasonic GX80||Four Thirds||15.8||4592||3448||4K/30p||22.9||12.6||662||71|
|6.||Panasonic G7||Four Thirds||15.8||4592||3448||4K/30p||..||..||..||..|
|7.||Panasonic GF7||Four Thirds||15.8||4592||3448||1080/60p||..||..||..||..|
|8.||Panasonic GM5||Four Thirds||15.8||4592||3448||1080/60p||22.1||11.7||721||66|
|9.||Panasonic G6||Four Thirds||15.9||4608||3456||1080/60p||21.3||11.5||639||61|
|10.||Panasonic GF6||Four Thirds||15.8||4592||3448||1080/60i||20.7||10.6||622||54|
|11.||Panasonic GM1||Four Thirds||15.8||4592||3448||1080/60i||22.3||11.7||660||66|
|12.||Panasonic GF5||Four Thirds||12.0||4000||3000||1080/60i||21.4||11.6||618||61|
|13.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|14.||Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|15.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|16.||Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|17.||Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
Many modern cameras are not only capable of taking still images, but can also record movies. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A7S III provides a faster frame rate than the GX800. It can shoot movie footage at 4K/120p, while the Panasonic is limited to 4K/30p.
Apart from body and sensor, cameras can and do differ across a range of features. For example, the A7S III has an electronic viewfinder (9440k dots), which can be very helpful when shooting in bright sunlight. In contrast, the GX800 relies on live view and the rear LCD for framing. The table below summarizes some of the other core capabilities of the Panasonic GX800 and Sony A7S III in connection with corresponding information for a sample of similar cameras.
|2.||Sony A7S III||9440||n||3.0||1440||swivel||Y||1/8000s||10.0||n||Y|
|13.||Sony A7R IV||5760||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|14.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|16.||Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|17.||Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The GX800 has one, while the A7S III does not. While the built-in flash of the GX800 is not very powerful, it can at times be useful as a fill-in light.Both cameras have an articulated rear screen that can be turned to be front-facing. This feature will be particularly appreciated by vloggers and photographers who are interested in taking selfies.
The reported shutter speed information refers to the use of the mechanical shutter. Yet, some cameras only have an electronic shutter, while others have an electronic shutter in addition to a mechanical one. In fact, both cameras under consideration feature an electronic shutter, which makes completely silent shooting possible. However, this mode is less suitable for photographing moving objects (risk of rolling shutter) or shooting under artificial light sources (risk of flickering).
The Panasonic GX800 has an intervalometer built-in. This enables the photographer to capture time lapse sequences, such as flower blooming, a sunset or moon rise, without purchasing an external camera trigger and related software.
The GX800 writes its imaging data to SDXC cards, while the A7S III uses CFexpress or SDXC cards. The A7S III features dual card slots, which can be very useful in case a memory card fails. In contrast, the GX800 only has one slot. The A7S III supports UHS-II cards (on both slots), while the GX800 can use UHS-I cards.
For some imaging applications, the extent to which a camera can communicate with its environment can be an important aspect in the camera decision process. The table below provides an overview of the connectivity of the Panasonic Lumix DMC-GX800 and Sony Alpha 7S III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|2.||Sony A7S III||Y||stereo||mono||Y||Y||full||3.2||Y||-||Y|
|13.||Sony A7R IV||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|14.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|16.||Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|17.||Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the A7S III has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The GX800 lacks such a headphone port.
Both the GX800 and the A7S III are recent models that are part of the current product line-up. The GX800 replaced the earlier Panasonic GF7, while the A7S III followed on from the Sony A7S II. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Panasonic and Sony websites.
So what is the bottom line? Is there a clear favorite between the Panasonic GX800 and the Sony A7S III? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.
Reasons to prefer the Panasonic Lumix DMC-GX800:
- More detail: Offers more megapixels (15.8 vs 12MP) with a 13% higher linear resolution.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More compact: Is smaller (107x65mm vs 127x97mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 430g or 62 percent) and hence easier to carry around.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (84 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in January 2017).
Advantages of the Sony Alpha 7S III:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better image quality: Scores substantially higher (13 points) in the DXO overall evaluation.
- More dynamic range: Captures a broader range of light and dark details (0.6 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (2.1 stops ISO advantage).
- Better video: Provides higher movie framerates (4K/120p versus 4K/30p).
- Better sound: Can connect to an external microphone for higher quality sound recording.
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- Easier framing: Has an electronic viewfinder for image composition and settings control.
- More detailed LCD: Has a higher resolution rear screen (1440k vs 1040k dots).
- More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/500s) to freeze action.
- Longer lasting: Gets more shots (600 versus 210) out of a single battery charge.
- Easier travel charging: Can be conveniently charged via its USB port.
- Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
- Faster data transfer: Supports a more advanced USB protocol (3.2 vs 2.0).
- More solid recording: Has a full-sized HDMI port for a sturdy connection to an external recorder.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
- Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
- More modern: Reflects 3 years and 6 months of technical progress since the GX800 launch.
If the count of relative strengths (bullet points above) is taken as a measure, the A7S III is the clear winner of the contest (22 : 8 points). However, the relevance of individual strengths will vary across photographers, so that you might want to apply your own weighing scheme to the summary points when reflecting and deciding on a new camera. A professional wildlife photographer will view the differences between cameras in a way that diverges from the perspective of a family photog, and a person interested in architecture has distinct needs from a sports shooter. Hence, the decision which camera is best and worth buying is often a very personal one.
How about other alternatives? Do the specifications of the Panasonic GX800 and the Sony A7S III place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera listing whether the two cameras rank among the cream of the crop.
In any case, while the comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it says little about, for example, the shooting experience and imaging performance of the GX800 and the A7S III in practical situations. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate.
This is why hands-on reviews by experts are important. The following table reports the overall ratings of the cameras as published by some of the major camera review sites (amateurphotographer [AP], cameralabs [CL], dpreview [DPR], ephotozine [EPZ], photographyblog [PB]). As can be seen, the professional reviewers agree in many cases on the quality of different cameras, but sometimes their assessments diverge, reinforcing the earlier point that a camera decision is often a very personal choice.
|1.||Panasonic GX800||..||+||76/100||4.5/5||4.5/5||Jan 2017||549|
|2.||Sony A7S III||..||+ +||91/100||4.5/5||5/5||Jul 2020||3,499|
|3.||Canon M100||3/5||+||..||4/5||3.5/5||Aug 2017||499|
|4.||Canon M10||..||..||..||..||4/5||Oct 2015||499|
|5.||Panasonic GX80||4.5/5||+ +||82/100||5/5||5/5||Apr 2016||799|
|6.||Panasonic G7||4/5||+ +||80/100||5/5||4.5/5||May 2015||649|
|7.||Panasonic GF7||4/5||+||..||4.5/5||4.5/5||Jan 2015||499|
|8.||Panasonic GM5||3.5/5||+||77/100||5/5||4.5/5||Sep 2014||749|
|9.||Panasonic G6||4/5||+ +||..||5/5||4.5/5||Apr 2013||599|
|10.||Panasonic GF6||..||+ +||..||4.5/5||4.5/5||Apr 2013||499|
|11.||Panasonic GM1||3/5||+||78/100||5/5||4.5/5||Oct 2013||749|
|12.||Panasonic GF5||3/5||..||..||4.5/5||4.5/5||Apr 2012||499|
|13.||Sony A7R IV||5/5||+||91/100||4.5/5||5/5||Jul 2019||3,499|
|14.||Sony A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|15.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|16.||Sony A7R II||5/5||+ +||90/100||5/5||5/5||Jun 2015||3,199|
|17.||Sony A7S II||5/5||+||..||4.5/5||5/5||Sep 2015||2,999|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
Care should be taken when interpreting the review scores above, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.
Other camera comparisons
Did this review help to inform your camera decision process? In case you are interested in seeing how other cameras pair up, just make your choice using the following search menu. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.
Specifications: Panasonic GX800 vs Sony A7S III
|Camera Model||Panasonic GX800||Sony A7S III|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Micro Four Thirds lenses||Sony E mount lenses|
|Launch Date||January 2017||July 2020|
|Launch Price||USD 549||USD 3,499|
|Sensor Specs||Panasonic GX800||Sony A7S III|
|Sensor Format||Four Thirds Sensor||Full Frame Sensor|
|Sensor Size||17.3 x 13.0 mm||35.6 x 23.8 mm|
|Sensor Area||224.9 mm2||847.28 mm2|
|Sensor Diagonal||21.6 mm||42.8 mm|
|Sensor Resolution||15.8 Megapixels||12 Megapixels|
|Image Resolution||4592 x 3448 pixels||4240 x 2832 pixels|
|Pixel Pitch||3.77 μm||8.40 μm|
|Pixel Density||7.04 MP/cm2||1.42 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||4K/30p Video||4K/120p Video|
|ISO Setting||200 - 25,600 ISO||80 - 102,400 ISO|
|ISO Boost||100 - 25,600 ISO||40 - 409,600 ISO|
|Image Processor||Venus||BIONZ XR|
|DXO Sensor Quality (score)||73||86|
|DXO Color Depth (bits)||23.2||23.7|
|DXO Dynamic Range (EV)||13.3||13.9|
|DXO Low Light (ISO)||586||2520|
|Screen Specs||Panasonic GX800||Sony A7S III|
|Viewfinder Type||no viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%|
|Viewfinder Resolution||9440k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1040k dots||1440k dots|
|LCD Attachment||Tilting screen||Swivel screen|
|Shooting Specs||Panasonic GX800||Sony A7S III|
|Focus System||Contrast-detect AF||Contrast-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/500s||1/8000s|
|Continuous Shooting||10 shutter flaps/s||10 shutter flaps/s|
|Electronic Shutter||up to 1/16000s||YES|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||SDXC cards||CFexpress or SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-I||Dual UHS-II|
|Connectivity Specs||Panasonic GX800||Sony A7S III|
|External Flash||no Hotshoe||Hotshoe|
|USB Connector||USB 2.0||USB 3.2|
|HDMI Port||micro HDMI||full HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Panasonic GX800||Sony A7S III|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||210 shots per charge||600 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
107 x 65 x 33 mm
(4.2 x 2.6 x 1.3 in)
127 x 97 x 81 mm
(5.0 x 3.8 x 3.2 in)
|Camera Weight||269 g (9.5 oz)||699 g (24.7 oz)|