Sony A7R III versus Panasonic GX8
The Sony Alpha A7R III and the Panasonic Lumix DMC-GX8 are two enthusiast cameras that were officially introduced, respectively, in October 2017 and July 2015. Both the A7R III and the GX8 are mirrorless interchangeable lens cameras that are based on a full frame (A7R III) and a Four Thirds (GX8) sensor. The Sony has a resolution of 42.2 megapixel, whereas the Panasonic provides 20.2 MP. Read on to find out how these two cameras compare with respect to their size, their sensors, their features, and their reception by expert reviewers.
Body comparison: Sony A7R III vs Panasonic GX8
The physical size and weight of the Sony A7R III and the Panasonic GX8 are illustrated in the side-by-side display below. Three successive views from the front, the top, and the rear are shown. All width, height and depth dimensions are rounded to the nearest millimeter. If you prefer, you can also use the toggle button to switch to a comparison in percentage terms (in this case, the camera on the left side – the A7R III – represents the basis for the calculations across all the size and weight measures).
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Panasonic GX8 is notably smaller (15 percent) than the Sony A7R III. Moreover, the GX8 is markedly lighter (25 percent) than the A7R III. 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 find an overview of optics for the two cameras in the Sony FE Lens Catalog (A7R III) and the Micro Four Thirds Lens Catalog (GX8). 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.
The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. If you want to switch the focus of the display and review another camera pair, just select a new right or left comparator from among the camera models in the table. Alternatively, you can also move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|Camera Body Specifications|
|Sony A7R III»||5.0 in||3.8 in||2.9 in||22.9 oz||650||Y||Oct 2017||3,199|
|Panasonic GX8«||5.2 in||3.1 in||2.5 in||17.2 oz||330||Y||Jul 2015||1,199||-|
|Hasselblad X1D« »||5.9 in||3.9 in||2.8 in||25.6 oz||..||Y||Jun 2016||8,995|
|Olympus E-M1 II« »||5.3 in||3.6 in||2.6 in||20.2 oz||440||Y||Sep 2016||1,999|
|Olympus E-M5 II« »||4.9 in||3.3 in||1.8 in||16.5 oz||310||Y||Feb 2015||1,099|
|Panasonic GX9« »||4.9 in||2.8 in||1.9 in||14.4 oz||260||n||Feb 2018||849|
|Panasonic GH5« »||5.5 in||3.9 in||3.4 in||25.6 oz||410||Y||Jan 2017||1,999|
|Panasonic GX7« »||4.8 in||2.8 in||2.2 in||14.2 oz||350||n||Aug 2013||999||-|
|Sony A7 III« »||5.0 in||3.8 in||2.9 in||22.9 oz||610||Y||Feb 2018||1,999|
|Sony A9« »||5.0 in||3.8 in||2.5 in||23.7 oz||650||Y||Apr 2017||4,499|
|Sony A99 II« »||5.6 in||4.1 in||3.0 in||29.9 oz||490||Y||Sep 2016||3,199|
|Sony A6500« »||4.7 in||2.6 in||2.1 in||16.0 oz||350||Y||Oct 2016||1,399|
|Sony A7R II« »||5.0 in||3.8 in||2.4 in||22.0 oz||290||Y||Jun 2015||3,199||-|
|Sony A7S II« »||5.0 in||3.8 in||2.4 in||22.1 oz||370||Y||Sep 2015||2,999|
|Sony A7 II« »||5.0 in||3.8 in||2.4 in||21.1 oz||350||Y||Nov 2014||1,999||-|
|Sony A7R« »||5.0 in||3.7 in||1.9 in||16.4 oz||340||Y||Oct 2013||2,299||-|
|Sony A99« »||5.8 in||4.4 in||3.1 in||28.6 oz||500||Y||Sep 2012||2,799||-|
The price is, of course, an important factor in any camera decision. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The GX8 was launched at a markedly lower price (by 63 percent) than the A7R 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.
Sensor comparison: Sony A7R III vs Panasonic GX8
The size of the imaging sensor is a crucial determinant of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color depth than smaller pixel-units 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.
Of the two cameras under consideration, the Sony A7R III features a full frame sensor and the Panasonic GX8 a Four Thirds sensor. The sensor area in the GX8 is 74 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 2.0. The sensor in the A7R III has a native 3:2 aspect ratio, while the one in the GX8 offers a 4:3 aspect.
With 42.2MP, the A7R III offers a higher resolution than the GX8 (20.2MP), but the A7R III nevertheless has larger individual pixels (pixel pitch of 4.52μm versus 3.34μm for the GX8) due to its larger sensor. Moreover, the A7R III is a somewhat more recent model (by 2 years and 3 months) than the GX8, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels. Coming back to sensor resolution, it should be mentioned that the A7R III has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
Unlike the GX8, the A7R III has the capacity to capture high quality composite images 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).
Consistent information on actual sensor performance is available from DXO Mark for most cameras. 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 review, the A7R III provides substantially higher image quality than the GX8, with an overall score that is 25 points higher. This advantage is based on 2.5 bits higher color depth, 2.1 EV in additional dynamic range, and 2.1 stops in additional low light sensitivity. The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.
|Sony A7R III»||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|Panasonic GX8«||Four Thirds||20.2||5184||3888||4K/30p||23.5||12.6||806||75|
|Hasselblad X1D« »||Medium Format||51.3||8272||6200||1080/25p||26.2||14.8||4489||102|
|Olympus E-M1 II« »||Four Thirds||20.2||5184||3888||4K/30p||23.7||12.8||1312||80|
|Olympus E-M5 II« »||Four Thirds||15.9||4608||3456||1080/60p||23.0||12.5||842||73|
|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 GX7« »||Four Thirds||15.8||4592||3448||1080/60p||22.6||12.2||718||70|
|Sony A7 III« »||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|Sony A9« »||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|Sony A99 II« »||Full Frame||42.2||7952||5304||4K/30p||25.4||13.4||2317||92|
|Sony A6500« »||APS-C||24.0||6000||4000||4K/30p||24.5||13.7||1405||85|
|Sony A7R II« »||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|Sony A7S II« »||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|Sony A7 II« »||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|Sony A7R« »||Full Frame||36.2||7360||4912||1080/60p||25.6||14.1||2746||95|
|Sony A99« »||Full Frame||24.0||6000||4000||1080/60p||25.0||14.0||1555||89|
Many modern cameras cannot only take still pictures, but also record videos. 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).
Feature comparison: Sony A7R III vs Panasonic GX8
Beyond body and sensor, cameras can and do differ across a range of features. The two cameras under consideration are similar with respect to both having an electronic viewfinder. However, the one in the A7R III offers a substantially higher resolution than the one in the GX8 (3686k vs 2360k dots). The adjacent table lists some of the other core features of the Sony A7R III and Panasonic GX8 along with similar information for a selection of comparators. The full specs-sheets can be found in the camera manual or, for example, in the dpreview camera hub.
|Sony A7R III»||3686||n||3.0||1440||tilting||Y||8000||10.0||n||Y|
|Hasselblad X1D« »||2360||n||3.0||920||fixed||Y||2000||2.3||n||n|
|Olympus E-M1 II« »||2360||n||3.0||1037||swivel||Y||8000||18.0||n||Y|
|Olympus E-M5 II« »||2360||n||3.0||1037||swivel||Y||8000||10.0||n||Y|
|Panasonic GX9« »||2760||n||3.0||1240||tilting||Y||4000||9.0||Y||Y|
|Panasonic GH5« »||3680||n||3.2||1620||swivel||Y||8000||12.0||n||Y|
|Panasonic GX7« »||2760||n||3.0||1040||tilting||Y||8000||5.0||Y||Y|
|Sony A7 III« »||2359||n||3.0||922||tilting||Y||8000||10.0||n||Y|
|Sony A9« »||3686||n||3.0||1440||tilting||Y||8000||20.0||n||Y|
|Sony A99 II« »||2400||Y||3.0||1229||full-flex||n||8000||12.0||n||Y|
|Sony A6500« »||2300||n||3.0||922||tilting||Y||4000||11.0||Y||Y|
|Sony A7R II« »||2400||n||3.0||1229||tilting||n||8000||5.0||n||Y|
|Sony A7S II« »||2400||n||3.0||1229||tilting||n||8000||5.0||n||Y|
|Sony A7 II« »||2400||n||3.0||1230||tilting||n||8000||5.0||n||Y|
|Sony A7R« »||2400||n||3.0||1230||tilting||n||8000||4.0||n||n|
|Sony A99« »||2359||Y||3.0||1229||full-flex||n||8000||6.0||n||Y|
The A7R III is a current model that online retailers, such as amazon, will have in stock. In contrast, the GX8 has been discontinued (but it can be found pre-owned on eBay). As a replacement in the same line of cameras, the GX8 was succeeded by the Panasonic GX9.
Review summary: Sony A7R III vs Panasonic GX8
So how do things add up? Is there a clear favorite between the Sony A7R III and the Panasonic GX8? The listing below highlights the relative strengths of the two models.
Arguments in favor of the Sony Alpha A7R III:
- More detail: Offers more megapixels (42.2 vs 20.2MP) with a 48% higher linear resolution.
- 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 image quality: Scores substantially higher (25 points) in the DXO overall assessment.
- Richer colors: Generates images with noticeably better colors (2.5 bits more color depth).
- More dynamic range: Captures a larger spectrum of light and dark details (2.1 EV of extra DR).
- Better low-light sensitivity: Requires less light for good images (2.1 stops ISO advantage).
- More detailed viewfinder: Has higher resolution electronic viewfinder (3686k vs 2360k dots).
- More detailed LCD: Has a higher resolution rear screen (1440k vs 1040k dots).
- Longer lasting: Can take more shots (650 versus 330) on a single battery charge.
- More modern: Reflects 2 years and 3 months of technical progress since the GX8 launch.
Advantages of the Panasonic Lumix DMC-GX8:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- More flexible LCD: Has swivel screen for odd-angle shots in portrait or landscape orientation.
- More compact: Is smaller (133x78mm vs 127x96mm) and will fit more readily into a bag.
- Less heavy: Has a lower weight (by 163g or 25 percent) and is thus easier to take along.
- More affordable: Was introduced into a lower priced category (63 percent cheaper at launch).
- More heavily discounted: Has been around for much longer (launched in July 2015).
If the number of relative strengths (bullet points above) is taken as a guide, the A7R III is the clear winner of the match-up (11 : 6 points). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features before making a decision on a new camera.
In any case, while the comparison of technical specifications can provide a useful overview of the capabilities of different cameras, it remains partial and cannot reveal, for example, the handling experience and imaging performance when actually working with the A7R III or the GX8. 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 why hands-on reviews by experts are important. The adjacent table relays the overall verdicts of several of the most popular camera review sites (cameralabs, dpreview, ephotozine, imaging-resource, photographyblog). The detailed reviews can be accessed by clicking on the site logo in the table header.
|Sony A7R III»||HiRec||90/100||4.5/5||5/5||5/5||Oct 2017||3,199|
|Panasonic GX8«||Rec||82/100||4.5/5||5/5||4.5/5||Jul 2015||1,199||-|
|Hasselblad X1D« »||rev||-||-||-||4/5||Jun 2016||8,995|
|Olympus E-M1 II« »||HiRec||85/100||4.5/5||5/5||4.5/5||Sep 2016||1,999|
|Olympus E-M5 II« »||HiRec||81/100||5/5||4.5/5||5/5||Feb 2015||1,099|
|Panasonic GX9« »||Rec||-||4.5/5||-||4.5/5||Feb 2018||849|
|Panasonic GH5« »||HiRec||85/100||4.5/5||5/5||5/5||Jan 2017||1,999|
|Panasonic GX7« »||Rec||79/100||5/5||4.5/5||5/5||Aug 2013||999||-|
|Sony A7 III« »||HiRec||89/100||5/5||-||5/5||Feb 2018||1,999|
|Sony A9« »||HiRec||89/100||5/5||5/5||5/5||Apr 2017||4,499|
|Sony A99 II« »||-||85/100||4.5/5||4.5/5||4.5/5||Sep 2016||3,199|
|Sony A6500« »||HiRec||85/100||4.5/5||5/5||4.5/5||Oct 2016||1,399|
|Sony A7R II« »||HiRec||90/100||5/5||4.5/5||5/5||Jun 2015||3,199||-|
|Sony A7S II« »||Rec||-||4.5/5||5/5||5/5||Sep 2015||2,999|
|Sony A7 II« »||Rec||82/100||4.5/5||5/5||5/5||Nov 2014||1,999||-|
|Sony A7R« »||HiRec||82/100||4.5/5||5/5||5/5||Oct 2013||2,299||-|
|Sony A99« »||-||84/100||4.5/5||rev||4.5/5||Sep 2012||2,799||-|
The review scores listed above should be treated with care, though. The ratings are only valid when refering to cameras in the same category and of the same age. Hence, a score should always be seen in the context of the camera's market launch date and its price, and comparisons of ratings among very different cameras or across long time periods have little meaning. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.
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