Olympus E-M1 III vs Panasonic GX800
The Olympus OM-D E-M1 Mark III and the Panasonic Lumix DMC-GX800 (labelled Panasonic GX850 in some countries) are two digital cameras that were revealed to the public, respectively, in February 2020 and January 2017. Both the E-M1 III and the GX800 are mirrorless interchangeable lens cameras that are equipped with a Four Thirds sensor. The Olympus has a resolution of 20.2 megapixels, whereas the Panasonic provides 15.8 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 Olympus OM-D E-M1 Mark III and the Panasonic Lumix DMC-GX800? 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.
The physical size and weight of the Olympus E-M1 III and the Panasonic GX800 are illustrated 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 width, height and depth measures are rounded to the nearest millimeter.
The GX800 can be obtained in three different colors (black, silver, red), while the E-M1 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 Panasonic GX800 is considerably smaller (43 percent) than the Olympus E-M1 III. Moreover, the GX800 is substantially lighter (54 percent) than the E-M1 III. It is worth mentioning in this context that the E-M1 III is splash and dust resistant, 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. In this particular case, both cameras feature the same lens mount, so that they can use the same lenses. You can compare the optics available in the Micro Four Thirds Lens Catalog. 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 E-M1 III gets 420 shots out of its BLH-1 battery, while the GX800 can take 210 images on a single charge of its DMW-BLH7 power pack. The power pack in the E-M1 III can be charged via the USB port, so that it is not always necessary to take the battery charger along when travelling.
The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.
|1.||Olympus E-M1 III||134 mm||91 mm||69 mm||580 g||420||Y||Feb 2020||1,799|
|2.||Panasonic GX800||107 mm||65 mm||33 mm||269 g||210||n||Jan 2017||549|
|3.||Canon M10||108 mm||67 mm||35 mm||301 g||255||n||Oct 2015||499|
|4.||Fujifilm X-H1||140 mm||97 mm||86 mm||673 g||310||Y||Feb 2018||1,899|
|5.||Nikon Z6 II||134 mm||101 mm||70 mm||705 g||410||Y||Oct 2020||1,999|
|6.||Olympus E-M5 III||125 mm||85 mm||50 mm||414 g||310||Y||Oct 2019||1,199|
|7.||Olympus E-M1X||144 mm||147 mm||75 mm||997 g||870||Y||Jan 2019||2,999|
|8.||Olympus E-M1 II||134 mm||91 mm||67 mm||574 g||440||Y||Sep 2016||1,999|
|9.||Panasonic G90||130 mm||94 mm||77 mm||536 g||290||Y||Apr 2019||999|
|10.||Panasonic G9||137 mm||97 mm||92 mm||658 g||400||Y||Nov 2017||1,699|
|11.||Panasonic GH5||139 mm||98 mm||87 mm||725 g||410||Y||Jan 2017||1,999|
|12.||Panasonic GF7||107 mm||65 mm||33 mm||266 g||230||n||Jan 2015||499|
|13.||Panasonic G6||122 mm||85 mm||71 mm||390 g||340||n||Apr 2013||599|
|14.||Panasonic GF6||111 mm||65 mm||38 mm||323 g||340||n||Apr 2013||499|
|15.||Panasonic GF5||108 mm||67 mm||37 mm||267 g||360||n||Apr 2012||499|
|16.||Sony A7C||124 mm||71 mm||60 mm||509 g||740||Y||Sep 2020||1,799|
|17.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
Any camera decision will obviously take relative prices into account. The manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The GX800 was launched at a markedly lower price (by 69 percent) than the E-M1 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its background. On the downside, larger sensors are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.
Both cameras under consideration feature a Four Thirds sensor and have a format factor (sometimes also referred to as "crop factor") of 2.0. Within the spectrum of camera sensors, this places the review cameras among the medium-sized sensor cameras that aim to strike a balance between image quality and portability. Both cameras feature a native aspect ratio (sensor width to sensor height) of 4:3.
While the two cameras under review share the same sensor size, the E-M1 III offers a higher resolution of 20.2 megapixels, compared with 15.8 MP of the GX800. This megapixels advantage translates into a 13 percent gain in linear resolution. On the other hand, these sensor specs imply that the E-M1 III has a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.34μm versus 3.77μm for the GX800). In this context, it should be noted, however, that the E-M1 III is much more recent (by 3 years and 1 month) than the GX800, and its sensor will have benefitted from technological advances during this time that compensate for the smaller pixel size. Coming back to sensor resolution, it should be mentioned that neither of the two cameras has an anti-alias filter installed, so they are able to capture all the detail the sensor resolves.
The resolution advantage of the Olympus E-M1 III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the E-M1 III for good quality output (200 dots per inch) amounts to 25.9 x 19.4 inches or 65.8 x 49.4 cm, for very good quality (250 dpi) 20.7 x 15.6 inches or 52.7 x 39.5 cm, and for excellent quality (300 dpi) 17.3 x 13 inches or 43.9 x 32.9 cm. The corresponding values for the Panasonic GX800 are 23 x 17.2 inches or 58.3 x 43.8 cm for good quality, 18.4 x 13.8 inches or 46.7 x 35 cm for very good quality, and 15.3 x 11.5 inches or 38.9 x 29.2 cm for excellent quality prints.
The E-M1 III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the GX800, the E-M1 III has the capacity to capture high quality composite images (80MP) by combining multiple shots after shifting its sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).
The Olympus OM-D E-M1 Mark III has a native sensitivity range from ISO 200 to ISO 25600, which can be extended to ISO 64-25600. The corresponding ISO settings for the Panasonic Lumix DMC-GX800 are ISO 200 to ISO 25600, with the possibility to increase the ISO range to 100-25600.
Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. This service assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.
| DXO |
|1.||Olympus E-M1 III||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|2.||Panasonic GX800||Four Thirds||15.8||4592||3448||4K/30p||23.2||13.3||586||73|
|5.||Nikon Z6 II||Full Frame||24.3||6048||4024||4K/60p||..||..||..||..|
|6.||Olympus E-M5 III||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|7.||Olympus E-M1X||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|8.||Olympus E-M1 II||Four Thirds||20.2||5184||3888||4K/30p||23.7||12.8||1312||80|
|9.||Panasonic G90||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|10.||Panasonic G9||Four Thirds||20.2||5184||3888||4K/60p||..||..||..||..|
|11.||Panasonic GH5||Four Thirds||20.2||5184||3888||4K/60p||23.9||13.0||807||77|
|12.||Panasonic GF7||Four Thirds||15.8||4592||3448||1080/60p||..||..||..||..|
|13.||Panasonic G6||Four Thirds||15.9||4608||3456||1080/60p||21.3||11.5||639||61|
|14.||Panasonic GF6||Four Thirds||15.8||4592||3448||1080/60i||20.7||10.6||622||54|
|15.||Panasonic GF5||Four Thirds||12.0||4000||3000||1080/60i||21.4||11.6||618||61|
|16.||Sony A7C||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3407||95|
|17.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
Many modern cameras are not only capable of taking still images, but can also record movies. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, and both provide the same movie specifications (4K/30p).
Apart from body and sensor, cameras can and do differ across a variety of features. For example, the E-M1 III has an electronic viewfinder (2360k 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 following table reports on some other key feature differences and similarities of the Olympus E-M1 III, the Panasonic GX800, and comparable cameras.
|1.||Olympus E-M1 III||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|5.||Nikon Z6 II||3690||Y||3.2||2100||tilting||Y||1/8000s||14.0||n||Y|
|6.||Olympus E-M5 III||2360||n||3.0||1040||swivel||Y||1/8000s||10.0||n||Y|
|8.||Olympus E-M1 II||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|17.||Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
One feature that differentiates the E-M1 III and the GX800 is in-body image stabilization (IBIS). The E-M1 III reduces the risk of handshake-induced blur with all attached lenses, while the GX800 offers no blur reduction with lenses that themselves do not provide optical image stabilization.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 Olympus E-M1 III and the Panasonic GX800 both have 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.
Concerning the storage of imaging data, both the E-M1 III and the GX800 write their files to SDXC cards. The E-M1 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 E-M1 III supports UHS-II cards (on its first slot), 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 Olympus OM-D E-M1 Mark III and Panasonic Lumix DMC-GX800 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|1.||Olympus E-M1 III||Y||stereo||mono||Y||Y||micro||3.1||Y||-||Y|
|5.||Nikon Z6 II||Y||stereo||mono||Y||Y||micro||3.2||Y||-||Y|
|6.||Olympus E-M5 III||Y||stereo||mono||Y||-||micro||2.0||Y||-||Y|
|8.||Olympus E-M1 II||Y||stereo||mono||Y||Y||micro||3.0||Y||-||-|
|17.||Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
It is notable that the E-M1 III has a hotshoe, while the GX800 does not. This socket makes it possible to easily attach optional accessories, such as an external flash gun.
Studio photographers will appreciate that the Olympus E-M1 III (unlike the GX800) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the E-M1 III and the GX800 are recent models that are part of the current product line-up. The GX800 replaced the earlier Panasonic GF7, while the E-M1 III followed on from the Olympus E-M1 II. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Olympus and Panasonic websites.
So how do things add up? Is the Olympus E-M1 III better than the Panasonic GX800 or vice versa? Below is a summary of the relative strengths of each of the two contestants.
Arguments in favor of the Olympus OM-D E-M1 Mark III:
- More detail: Offers more megapixels (20.2 vs 15.8MP) with a 13% higher linear resolution.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- 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 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.
- Faster burst: Shoots at higher frequency (18 vs 10 flaps/sec) to capture the decisive moment.
- Longer lasting: Can take more shots (420 versus 210) on a single battery charge.
- Easier travel charging: Can be conveniently charged via its USB port.
- Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
- Sharper images: Has hand-shake reducing image stabilization built-in.
- Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
- Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- 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 1 month of technical progress since the GX800 launch.
Reasons to prefer the Panasonic Lumix DMC-GX800:
- More compact: Is smaller (107x65mm vs 134x91mm) and will fit more readily into a bag.
- Less heavy: Has a lower weight (by 311g or 54 percent) and is thus easier to take along.
- Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
- More affordable: Was introduced into a lower priced category (69 percent cheaper at launch).
- More heavily discounted: Has been around for much longer (launched in January 2017).
If the count of relative strengths (bullet points above) is taken as a measure, the E-M1 III is the clear winner of the match-up (20 : 5 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 Olympus E-M1 III and the Panasonic GX800 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 technical specifications can provide a useful overview of the capabilities of different cameras, it says little about, for example, the shooting experience and imaging performance of the E-M1 III and the GX800 in practical situations. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.
This is why hands-on reviews by experts are important. The table below provides a synthesis of the camera assessments of some of the best known photo-gear 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.||Olympus E-M1 III||5/5||..||83/100||4.5/5||4/5||Feb 2020||1,799|
|2.||Panasonic GX800||..||+||76/100||4.5/5||4.5/5||Jan 2017||549|
|3.||Canon M10||..||..||..||..||4/5||Oct 2015||499|
|4.||Fujifilm X-H1||..||+||86/100||4.5/5||4.5/5||Feb 2018||1,899|
|5.||Nikon Z6 II||4.5/5||..||89/100||4.5/5||4.5/5||Oct 2020||1,999|
|6.||Olympus E-M5 III||5/5||+||82/100||4.5/5||4.5/5||Oct 2019||1,199|
|7.||Olympus E-M1X||4.5/5||o||..||4.5/5||..||Jan 2019||2,999|
|8.||Olympus E-M1 II||5/5||+ +||85/100||4.5/5||4.5/5||Sep 2016||1,999|
|9.||Panasonic G90||4.5/5||+||83/100||4.5/5||4.5/5||Apr 2019||999|
|10.||Panasonic G9||..||+ +||85/100||5/5||5/5||Nov 2017||1,699|
|11.||Panasonic GH5||4.5/5||+ +||85/100||4.5/5||5/5||Jan 2017||1,999|
|12.||Panasonic GF7||4/5||+||..||4.5/5||4.5/5||Jan 2015||499|
|13.||Panasonic G6||4/5||+ +||..||5/5||4.5/5||Apr 2013||599|
|14.||Panasonic GF6||..||+ +||..||4.5/5||4.5/5||Apr 2013||499|
|15.||Panasonic GF5||3/5||..||..||4.5/5||4.5/5||Apr 2012||499|
|16.||Sony A7C||3.5/5||..||86/100||4/5||4/5||Sep 2020||1,799|
|17.||Sony A7 III||..||+ +||89/100||5/5||5/5||Feb 2018||1,999|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The review scores listed above should be treated with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. A score, therefore, has to be seen in close connection to the price and market introduction time of the camera, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. It should also be noted that some of the review sites have over time altered the way they render their verdicts.
Other camera comparisons
Did this review help to inform your camera decision process? In case you would like to check on the differences and similarities of other camera models, just make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
Specifications: Olympus E-M1 III vs Panasonic GX800
Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.
|Camera Model||Olympus E-M1 III||Panasonic GX800|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Micro Four Thirds lenses||Micro Four Thirds lenses|
|Launch Date||February 2020||January 2017|
|Launch Price||USD 1,799||USD 549|
|Sensor Specs||Olympus E-M1 III||Panasonic GX800|
|Sensor Format||Four Thirds Sensor||Four Thirds Sensor|
|Sensor Size||17.3 x 13.0 mm||17.3 x 13.0 mm|
|Sensor Area||224.9 mm2||224.9 mm2|
|Sensor Diagonal||21.6 mm||21.6 mm|
|Sensor Resolution||20.2 Megapixels||15.8 Megapixels|
|Image Resolution||5184 x 3888 pixels||4592 x 3448 pixels|
|Pixel Pitch||3.34 μm||3.77 μm|
|Pixel Density||8.96 MP/cm2||7.04 MP/cm2|
|Moiré control||no AA filter||no AA filter|
|Movie Capability||4K/30p Video||4K/30p Video|
|ISO Setting||200 - 25,600 ISO||200 - 25,600 ISO|
|ISO Boost||64 - 25,600 ISO||100 - 25,600 ISO|
|Image Processor||TruePic IX||Venus|
|DXO Sensor Quality (score)||..||73|
|DXO Color Depth (bits)||..||23.2|
|DXO Dynamic Range (EV)||..||13.3|
|DXO Low Light (ISO)||..||586|
|Screen Specs||Olympus E-M1 III||Panasonic GX800|
|Viewfinder Type||Electronic viewfinder||no viewfinder|
|Viewfinder Field of View||100%|
|Viewfinder Resolution||2360k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1037k dots||1040k dots|
|LCD Attachment||Swivel screen||Tilting screen|
|Shooting Specs||Olympus E-M1 III||Panasonic GX800|
|Focus System||On-Sensor Phase-detect||Contrast-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/500s|
|Continuous Shooting||18 shutter flaps/s||10 shutter flaps/s|
|Electronic Shutter||up to 1/32000s||up to 1/16000s|
|Time-Lapse Photography||Intervalometer built-in||Intervalometer built-in|
|Image Stabilization||In-body stabilization||Lens stabilization only|
|Fill Flash||no On-Board Flash||Build-in Flash|
|Storage Medium||SDXC cards||SDXC cards|
|Second Storage Option||Dual card slots||Single card slot|
|UHS card support||Single UHS-II||UHS-I|
|Connectivity Specs||Olympus E-M1 III||Panasonic GX800|
|External Flash||Hotshoe||no Hotshoe|
|Studio Flash||PC Sync socket||no PC Sync|
|USB Connector||USB 3.1||USB 2.0|
|HDMI Port||micro HDMI||micro HDMI|
|Microphone Port||External MIC port||no MIC socket|
|Headphone Socket||Headphone port||no Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Bluetooth Support||Bluetooth built-in||no Bluetooth|
|Body Specs||Olympus E-M1 III||Panasonic GX800|
|Environmental Sealing||Weathersealed body||not weather sealed|
|Battery Life (CIPA)||420 shots per charge||210 shots per charge|
|In-Camera Charging||USB charging||no USB charging|
134 x 91 x 69 mm
(5.3 x 3.6 x 2.7 in)
107 x 65 x 33 mm
(4.2 x 2.6 x 1.3 in)
|Camera Weight||580 g (20.5 oz)||269 g (9.5 oz)|
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