Panasonic G9 vs Sony A7 III
The Panasonic Lumix DC-G9 and the Sony Alpha A7 III are two enthusiast cameras that were announced, respectively, in November 2017 and February 2018. Both the G9 and the A7 III are mirrorless interchangeable lens cameras that are based on a Four Thirds (G9) and a full frame (A7 III) sensor. The Panasonic has a resolution of 20.2 megapixels, whereas the Sony provides 24 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 DC-G9 and the Sony Alpha A7 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.
The side-by-side display below illustrates the physical size and weight of the Panasonic G9 and the Sony A7 III. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All width, height and depth measures are rounded to the nearest millimeter.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A7 III is notably smaller (8 percent) than the Panasonic G9. Moreover, the A7 III is slightly lighter (1 percent) than the G9. In this context, it is worth noting that both cameras are splash and dust-proof and can, hence, be used in inclement weather conditions or harsh environments.
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 (G9) and the Sony FE Lens Catalog (A7 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 G9 gets 400 shots out of its DMW-BLF19 battery, while the A7 III can take 610 images on a single charge of its NP-FZ100 power pack. The battery packs of both cameras can be charged via USB, which can be very convenient when travelling.
The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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.
|Panasonic G9||137 mm||97 mm||92 mm||658 g||400||Y||Nov 2017||1,699|
|Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|Canon 6D Mark II||144 mm||111 mm||75 mm||765 g||1200||Y||Jun 2017||1,999|
|Fujifilm X-H1||140 mm||97 mm||86 mm||673 g||310||Y||Feb 2018||1,899|
|Olympus E-M1 III||134 mm||91 mm||69 mm||580 g||420||Y||Feb 2020||1,799|
|Olympus E-M1 II||134 mm||91 mm||67 mm||574 g||440||Y||Sep 2016||1,999|
|Panasonic GH5s||139 mm||98 mm||87 mm||660 g||440||Y||Jan 2018||2,499|
|Panasonic GX9||124 mm||72 mm||47 mm||407 g||260||n||Feb 2018||849|
|Panasonic GH5||139 mm||98 mm||87 mm||725 g||410||Y||Jan 2017||1,999|
|Panasonic G85||128 mm||89 mm||74 mm||505 g||330||Y||Sep 2016||899|
|Panasonic GX8||133 mm||78 mm||63 mm||487 g||330||Y||Jul 2015||1,199|
|Panasonic GH4||133 mm||93 mm||84 mm||560 g||500||Y||Feb 2014||1,499|
|Sony A9 II||129 mm||96 mm||76 mm||678 g||690||Y||Oct 2019||4,499|
|Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|Sony A7||127 mm||94 mm||48 mm||474 g||340||Y||Oct 2013||1,699|
|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 G9 was launched at a somewhat lower price (by 15 percent) than the A7 III, which makes it more attractive for photographers on a tight budget. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.
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. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better isolate a subject from the background. On the downside, larger sensors tend to be more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Panasonic G9 features a Four Thirds sensor and the Sony A7 III a full frame sensor. The sensor area in the A7 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 G9 has a native 4:3 aspect ratio, while the one in the A7 III offers a 3:2 aspect.
With 24MP, the A7 III offers a higher resolution than the G9 (20.2MP), but the A7 III nevertheless has larger individual pixels (pixel pitch of 5.94μm versus 3.34μm for the G9) due to its larger sensor. Moreover, the A7 III is a somewhat more recent model (by 3 months) than the G9, and its sensor might 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 G9 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Sony A7 III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7 III for good quality output (200 dots per inch) amounts to 30 x 20 inches or 76.2 x 50.8 cm, for very good quality (250 dpi) 24 x 16 inches or 61 x 40.6 cm, and for excellent quality (300 dpi) 20 x 13.3 inches or 50.8 x 33.9 cm. The corresponding values for the Panasonic G9 are 25.9 x 19.4 inches or 65.8 x 49.4 cm for good quality, 20.7 x 15.6 inches or 52.7 x 39.5 cm for very good quality, and 17.3 x 13 inches or 43.9 x 32.9 cm for excellent quality prints.
The A7 III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the A7 III, the G9 has the capacity to capture high quality composite images (80.6MP) 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 Panasonic Lumix DC-G9 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 A7 III are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.
Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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 table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
| DXO |
|Panasonic G9||Four Thirds||20.2||5184||3888||4K/60p||..||..||..||..|
|Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|Canon 6D Mark II||Full Frame||26.0||6240||4160||1080/60p||24.4||11.9||2862||85|
|Olympus E-M1 III||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|Olympus E-M1 II||Four Thirds||20.2||5184||3888||4K/30p||23.7||12.8||1312||80|
|Panasonic GH5s||Four Thirds||9.9||3680||2700||4K/60p||..||..||..||..|
|Panasonic GX9||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|Panasonic GH5||Four Thirds||20.2||5184||3888||4K/60p||23.9||13.0||807||77|
|Panasonic G85||Four Thirds||15.8||4592||3448||4K/30p||22.8||12.5||656||71|
|Panasonic GX8||Four Thirds||20.2||5184||3888||4K/30p||23.5||12.6||806||75|
|Panasonic GH4||Four Thirds||15.9||4608||3456||4K/30p||23.2||12.8||791||74|
|Sony A9 II||Full Frame||24.0||6000||4000||4K/30p||25.0||14.0||3434||93|
|Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|Sony A7||Full Frame||24.0||6000||4000||1080/60p||24.8||14.2||2248||90|
Many modern cameras are not only capable of taking still images, but can also record movies. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the G9 provides a higher frame rate than the A7 III. It can shoot video footage at 4K/60p, while the Sony is limited to 4K/30p.
Apart from body and sensor, cameras can and do differ across a variety of features. The two cameras under consideration are similar with respect to both having an electronic viewfinder. However, the one in the G9 offers a substantially higher resolution than the one in the A7 III (3680k vs 2359k dots). The table below summarizes some of the other core capabilities of the Panasonic G9 and Sony A7 III in connection with corresponding information for a sample of similar cameras.
|Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
|Canon 6D Mark II||optical||Y||3.0||1040||swivel||Y||1/4000s||6.5||n||n|
|Olympus E-M1 III||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|Olympus E-M1 II||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|Sony A9 II||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
One feature that is present on the G9, but is missing on the A7 III is a top-level LCD. While being, of course, smaller than the rear screen, the control panel conveys some of the essential shooting information and can be convenient for quick and easy settings verification.The G9 has an articulated LCD that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in snapping selfies. In contrast, the A7 III does not have a selfie-screen.
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 G9 and the Sony A7 III 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.
The G9 writes its imaging data to SDXC cards, while the A7 III uses SDXC or Memory Stick PRO Duo cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. However, while the G9 supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s) on both slots, the A7 III supports UHS-II only on its first slot and UHS-I (data transfer speed up to 104 MB/s) on the second one.
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 DC-G9 and Sony Alpha A7 III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|Canon 6D Mark II||Y||stereo||mono||Y||-||mini||2.0||Y||Y||Y|
|Olympus E-M1 III||Y||stereo||mono||Y||Y||micro||3.1||Y||-||Y|
|Olympus E-M1 II||Y||stereo||mono||Y||Y||micro||3.0||Y||-||-|
|Sony A9 II||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
Studio photographers will appreciate that the Panasonic G9 (unlike the A7 III) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the G9 and the A7 III are recent models that are part of the current product line-up. The A7 III replaced the earlier Sony A7 II, while the G9 does not have a direct predecessor. 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 how do things add up? Is there a clear favorite between the Panasonic G9 and the Sony A7 III? Which camera is better? The listing below highlights the relative strengths of the two models.
Reasons to prefer the Panasonic Lumix DC-G9:
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Better video: Provides higher movie framerates (4K/60p versus 4K/30p).
- More detailed viewfinder: Has higher resolution electronic viewfinder (3680k vs 2359k dots).
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.83x vs 0.78x).
- Easier setting verification: Features an LCD display on top to control shooting parameters.
- More detailed LCD: Has a higher resolution rear screen (1040k vs 922k dots).
- More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- Faster burst: Shoots at higher frequency (20 vs 10 flaps/sec) to capture the decisive moment.
- More solid recording: Has a full-sized HDMI port for a sturdy connection to an external recorder.
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- More affordable: Was introduced into a lower priced segment (15 percent cheaper at launch).
- More heavily discounted: Has been on the market for longer (launched in November 2017).
Advantages of the Sony Alpha A7 III:
- More detail: Has more megapixels (24 vs 20.2MP), which boosts linear resolution by 11%.
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better image quality: Features bigger pixels on a larger sensor for higher quality imaging.
- Richer colors: The pixel size advantage translates into images with better, more accurate colors.
- More dynamic range: Larger pixels capture a wider spectrum of light and dark details.
- Better low-light sensitivity: Larger pixels means good image quality even under poor lighting.
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- Longer lasting: Gets more shots (610 versus 400) out of a single battery charge.
- Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
- More modern: Was introduced somewhat (3 months) more recently.
If the number of relative strengths (bullet points above) is taken as a guide, the G9 is the clear winner of the match-up (14 : 10 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. A professional wedding photographer will view the differences between cameras in a way that diverges from the perspective of a travel photog, and a person interested in cityscapes has distinct needs from a macro 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 G9 and the Sony A7 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 remains incomplete and does no justice, for example, to the way the G9 or the A7 III perform in practice. At times, user reviews, such as those published at amazon, address these issues in a useful manner, but such feedback is on many occasions incomplete, inconsistent, and unreliable.
This is where reviews by experts come in. The table below provides a synthesis of the camera assessments of some of the best known photo-gear review sites (cameralabs, dpreview, ephotozine, imaging-resource, and photographyblog). 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.
|Panasonic G9||+ +||85/100||5/5||5/5||5/5||Nov 2017||1,699|
|Sony A7 III||+ +||89/100||5/5||5/5||5/5||Feb 2018||1,999|
|Canon 6D Mark II||+||80/100||4.5/5||4/5||4/5||Jun 2017||1,999|
|Fujifilm X-H1||+||86/100||4.5/5||..||4.5/5||Feb 2018||1,899|
|Olympus E-M1 III||..||83/100||4.5/5||..||4/5||Feb 2020||1,799|
|Olympus E-M1 II||+ +||85/100||4.5/5||5/5||4.5/5||Sep 2016||1,999|
|Panasonic GH5s||..||84/100||4.5/5||5/5||4.5/5||Jan 2018||2,499|
|Panasonic GX9||+||84/100||4.5/5||4.5/5||4.5/5||Feb 2018||849|
|Panasonic GH5||+ +||85/100||4.5/5||5/5||5/5||Jan 2017||1,999|
|Panasonic G85||+ +||84/100||5/5||4.5/5||4.5/5||Sep 2016||899|
|Panasonic GX8||+||82/100||4.5/5||5/5||4.5/5||Jul 2015||1,199|
|Panasonic GH4||+ +||85/100||5/5||5/5||5/5||Feb 2014||1,499|
|Sony A9 II||..||90/100||5/5||..||5/5||Oct 2019||4,499|
|Sony A9||+ +||89/100||5/5||5/5||5/5||Apr 2017||4,499|
|Sony A7 II||+||82/100||4.5/5||5/5||5/5||Nov 2014||1,999|
|Sony A7||+ +||80/100||5/5||4.5/5||5/5||Oct 2013||1,699|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The above review scores should be interpreted with care, though. The assessments were made in relation to similar cameras of the same technological generation. 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. 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 would like to check on the differences and similarities of other camera models, just use the search menu below. 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 G9 vs Sony A7 III
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||Panasonic G9||Sony A7 III|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Micro Four Thirds lenses||Sony E mount lenses|
|Launch Date||November 2017||February 2018|
|Launch Price||USD 1,699||USD 1,999|
|Sensor Specs||Panasonic G9||Sony A7 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||20.2 Megapixels||24 Megapixels|
|Image Resolution||5184 x 3888 pixels||6000 x 4000 pixels|
|Pixel Pitch||3.34 μm||5.94 μm|
|Pixel Density||8.96 MP/cm2||2.83 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||4K/60p Video||4K/30p Video|
|ISO Setting||200 - 25,600 ISO||100 - 51,200 ISO|
|ISO Boost||100 - 25,600 ISO||50 - 204,800 ISO|
|Image Processor||Venus 10||BIONZ X|
|DXO Sensor Quality (score)||..||96|
|DXO Color Depth (bits)||..||25.0|
|DXO Dynamic Range (EV)||..||14.7|
|DXO Low Light (ISO)||..||3730|
|Screen Specs||Panasonic G9||Sony A7 III|
|Viewfinder Type||Electronic viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||3680k dots||2359k dots|
|Top-Level Screen||Control Panel||no Top Display|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1040k dots||922k dots|
|LCD Attachment||Swivel screen||Tilting screen|
|Shooting Specs||Panasonic G9||Sony A7 III|
|Focus System||Contrast-detect AF||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/8000s|
|Continuous Shooting||20 shutter flaps/s||10 shutter flaps/s|
|Shutter Life Expectancy||200 000 actuations||200 000 actuations|
|Electronic Shutter||up to 1/32000s||YES|
|Time-Lapse Photography||Intervalometer built-in||Intervalometer built-in|
|Image Stabilization||In-body stabilization||In-body stabilization|
|Fill Flash||no On-Board Flash||no On-Board Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Dual card slots||Dual card slots|
|UHS card support||Dual UHS-II||Single UHS-II|
|Connectivity Specs||Panasonic G9||Sony A7 III|
|Studio Flash||PC Sync socket||no PC Sync|
|USB Connector||USB 3.0||USB 3.1|
|HDMI Port||full HDMI||micro HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||Headphone port||Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Near-Field Communication||no NFC||NFC built-in|
|Bluetooth Support||Bluetooth built-in||Bluetooth built-in|
|Body Specs||Panasonic G9||Sony A7 III|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||400 shots per charge||610 shots per charge|
|In-Camera Charging||USB charging||USB charging|
137 x 97 x 92 mm
(5.4 x 3.8 x 3.6 in)
127 x 96 x 74 mm
(5.0 x 3.8 x 2.9 in)
|Camera Weight||658 g (23.2 oz)||650 g (22.9 oz)|
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