Olympus E-M1 III vs Sony A1
The Olympus OM-D E-M1 Mark III and the Sony A1 are two digital cameras that were announced, respectively, in February 2020 and January 2021. Both the E-M1 III and the A1 are mirrorless interchangeable lens cameras that are based on a Four Thirds (E-M1 III) and a full frame (A1) sensor. The Olympus has a resolution of 20.2 megapixels, whereas the Sony provides 49.8 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 Sony A1? 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 Olympus E-M1 III and the Sony A1 is provided in the side-by-side display below. 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 dimensions 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 A1 is somewhat larger (3 percent) than the Olympus E-M1 III. Moreover, the A1 is markedly heavier (27 percent) than the E-M1 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 compare the optics available for the two cameras in the Micro Four Thirds Lens Catalog (E-M1 III) and the Sony FE Lens Catalog (A1). 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 A1 can take 530 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 want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|1.||Olympus E-M1 III||134 mm||91 mm||69 mm||580 g||420||Y||Feb 2020||1,799|
|2.||Sony A1||129 mm||97 mm||81 mm||737 g||530||Y||Jan 2021||6,499|
|3.||Fujifilm X-H1||140 mm||97 mm||86 mm||673 g||310||Y||Feb 2018||1,899|
|4.||Nikon Z6 II||134 mm||101 mm||70 mm||705 g||410||Y||Oct 2020||1,999|
|5.||Olympus E-M5 III||125 mm||85 mm||50 mm||414 g||310||Y||Oct 2019||1,199|
|6.||Olympus E-M1X||144 mm||147 mm||75 mm||997 g||870||Y||Jan 2019||2,999|
|7.||Olympus E-M1 II||134 mm||91 mm||67 mm||574 g||440||Y||Sep 2016||1,999|
|8.||Panasonic G90||130 mm||94 mm||77 mm||536 g||290||Y||Apr 2019||999|
|9.||Panasonic G9||137 mm||97 mm||92 mm||658 g||400||Y||Nov 2017||1,699|
|10.||Panasonic GH5||139 mm||98 mm||87 mm||725 g||410||Y||Jan 2017||1,999|
|11.||Sony A7S III||127 mm||97 mm||81 mm||699 g||600||Y||Jul 2020||3,499|
|12.||Sony A7C||124 mm||71 mm||60 mm||509 g||740||Y||Sep 2020||1,799|
|13.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|14.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|15.||Sony A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|16.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|17.||Sony A7R II||127 mm||96 mm||60 mm||625 g||290||Y||Jun 2015||3,199|
|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 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 E-M1 III was launched at a markedly lower price (by 72 percent) than the A1, which puts it into a different market segment. 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 size of the sensor inside a digital camera is one of the key determinants 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. 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 Olympus E-M1 III features a Four Thirds sensor and the Sony A1 a full frame sensor. The sensor area in the A1 is 283 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 E-M1 III has a native 4:3 aspect ratio, while the one in the A1 offers a 3:2 aspect.
With 49.8MP, the A1 offers a higher resolution than the E-M1 III (20.2MP), but the A1 nevertheless has larger individual pixels (pixel pitch of 4.16μm versus 3.34μm for the E-M1 III) due to its larger sensor. Moreover, the A1 is a somewhat more recent model (by 11 months) than the E-M1 III, 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 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 Sony A1 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A1 for good quality output (200 dots per inch) amounts to 43.2 x 28.8 inches or 109.7 x 73.2 cm, for very good quality (250 dpi) 34.6 x 23 inches or 87.8 x 58.5 cm, and for excellent quality (300 dpi) 28.8 x 19.2 inches or 73.2 x 48.8 cm. The corresponding values for the Olympus E-M1 III 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.
Both cameras have the capacity to capture high quality composite images by combining multiple shots after shifting the 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 Sony A1 are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 500-102400.
For many cameras, data on sensor performance has been reported by DXO Mark. 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.||Sony A1||Full Frame||49.8||8640||5760||8k/30p||..||..||..||..|
|4.||Nikon Z6 II||Full Frame||24.3||6048||4024||4K/60p||..||..||..||..|
|5.||Olympus E-M5 III||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|6.||Olympus E-M1X||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|7.||Olympus E-M1 II||Four Thirds||20.2||5184||3888||4K/30p||23.7||12.8||1312||80|
|8.||Panasonic G90||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|9.||Panasonic G9||Four Thirds||20.2||5184||3888||4K/60p||..||..||..||..|
|10.||Panasonic GH5||Four Thirds||20.2||5184||3888||4K/60p||23.9||13.0||807||77|
|11.||Sony A7S III||Full Frame||12.0||4240||2832||4K/120p||23.7||13.9||2520||86|
|12.||Sony A7C||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3407||95|
|13.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|14.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|15.||Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|16.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|17.||Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
Many modern cameras cannot only take still pictures, but also record videos. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A1 provides a better video resolution than the E-M1 III. It can shoot movie footage at 8k/30p, while the Olympus is limited to 4K/30p.
Beyond body and sensor, cameras can and do differ across a range of features. The two cameras under review are similar with respect to both having an electronic viewfinder. However, the one in the A1 offers a substantially higher resolution than the one in the E-M1 III (9437k vs 2360k dots). The following table reports on some other key feature differences and similarities of the Olympus E-M1 III, the Sony A1, and comparable cameras.
|1.||Olympus E-M1 III||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|4.||Nikon Z6 II||3690||Y||3.2||2100||tilting||Y||1/8000s||14.0||n||Y|
|5.||Olympus E-M5 III||2360||n||3.0||1040||swivel||Y||1/8000s||10.0||n||Y|
|7.||Olympus E-M1 II||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|11.||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 A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
|15.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|17.||Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
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 Sony A1 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 E-M1 III writes its imaging data to SDXC cards, while the A1 uses CFexpress or SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. Both cameras support UHS-II cards, which provide for Ultra High Speed data transfer of up to 312 MB/s (the second slot of the E-M1 III supports only UHS-I, though).
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 Sony A1 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|
|4.||Nikon Z6 II||Y||stereo||mono||Y||Y||micro||3.2||Y||-||Y|
|5.||Olympus E-M5 III||Y||stereo||mono||Y||-||micro||2.0||Y||-||Y|
|7.||Olympus E-M1 II||Y||stereo||mono||Y||Y||micro||3.0||Y||-||-|
|11.||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 A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|15.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|17.||Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.
Both the E-M1 III and the A1 are recent models that are part of the current product line-up. The E-M1 III replaced the earlier Olympus E-M1 II, while the A1 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 Olympus and Sony websites.
So what conclusions can be drawn? Which of the two cameras – the Olympus E-M1 III or the Sony A1 – has the upper hand? Is one clearly better than the other? A synthesis of the relative strong points of each of the models is listed below.
Arguments in favor of the Olympus OM-D E-M1 Mark III:
- 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 (18 vs 10 flaps/sec) to capture the decisive moment.
- Less heavy: Is lighter (by 157g or 21 percent) and hence easier to carry around.
- More affordable: Was introduced into a lower priced category (72 percent cheaper at launch).
- More heavily discounted: Has been on the market for longer (launched in February 2020).
Reasons to prefer the Sony A1:
- More detail: Has more megapixels (49.8 vs 20.2MP), which boosts linear resolution by 60%.
- Better image quality: Is equipped with a larger and more technologically advanced sensor.
- Richer colors: The sensor size advantage translates into images with better, more accurate colors.
- More dynamic range: Larger sensor captures a wider spectrum of light and dark details.
- Better low-light sensitivity: Larger sensor produces good images even in poorly lit environments.
- Better video: Provides higher definition movie capture (8k/30p vs 4K/30p).
- More detailed viewfinder: Has higher resolution electronic viewfinder (9437k vs 2360k dots).
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.9x vs 0.83x).
- More detailed LCD: Has a higher resolution rear screen (1440k vs 1037k dots).
- Longer lasting: Gets more shots (530 versus 420) out of a single battery charge.
- Faster data transfer: Supports a more advanced USB protocol (3.2 vs 3.1).
- More modern: Was introduced somewhat (11 months) more recently.
If the number of relative strengths (bullet points above) is taken as a guide, the A1 is the clear winner of the contest (12 : 6 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 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 Olympus E-M1 III and the Sony A1 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 A1 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 expert reviews 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.||Sony A1||..||..||..||..||..||Jan 2021||6,499|
|3.||Fujifilm X-H1||..||+||86/100||4.5/5||4.5/5||Feb 2018||1,899|
|4.||Nikon Z6 II||4.5/5||..||89/100||4.5/5||4.5/5||Oct 2020||1,999|
|5.||Olympus E-M5 III||5/5||+||82/100||4.5/5||4.5/5||Oct 2019||1,199|
|6.||Olympus E-M1X||4.5/5||o||..||4.5/5||..||Jan 2019||2,999|
|7.||Olympus E-M1 II||5/5||+ +||85/100||4.5/5||4.5/5||Sep 2016||1,999|
|8.||Panasonic G90||4.5/5||+||83/100||4.5/5||4.5/5||Apr 2019||999|
|9.||Panasonic G9||..||+ +||85/100||5/5||5/5||Nov 2017||1,699|
|10.||Panasonic GH5||4.5/5||+ +||85/100||4.5/5||5/5||Jan 2017||1,999|
|11.||Sony A7S III||..||+ +||91/100||4.5/5||5/5||Jul 2020||3,499|
|12.||Sony A7C||3.5/5||..||86/100||4/5||4/5||Sep 2020||1,799|
|13.||Sony A7R IV||5/5||+||91/100||4.5/5||5/5||Jul 2019||3,499|
|14.||Sony A7 III||..||+ +||89/100||5/5||5/5||Feb 2018||1,999|
|15.||Sony A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|16.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|17.||Sony A7R II||5/5||+ +||90/100||5/5||5/5||Jun 2015||3,199|
|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. 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, please note that some of the review sites have changed their methodology and reporting over time.
Other camera comparisons
Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just use the search menu below. 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 Sony A1
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||Sony A1|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Micro Four Thirds lenses||Sony E mount lenses|
|Launch Date||February 2020||January 2021|
|Launch Price||USD 1,799||USD 6,499|
|Sensor Specs||Olympus E-M1 III||Sony A1|
|Sensor Format||Four Thirds Sensor||Full Frame Sensor|
|Sensor Size||17.3 x 13.0 mm||35.9 x 24.0 mm|
|Sensor Area||224.9 mm2||861.6 mm2|
|Sensor Diagonal||21.6 mm||43.2 mm|
|Sensor Resolution||20.2 Megapixels||49.8 Megapixels|
|Image Resolution||5184 x 3888 pixels||8640 x 5760 pixels|
|Pixel Pitch||3.34 μm||4.16 μm|
|Pixel Density||8.96 MP/cm2||5.78 MP/cm2|
|Moiré control||no AA filter||no AA filter|
|Movie Capability||4K/30p Video||8k/30p Video|
|ISO Setting||200 - 25,600 ISO||100 - 32,000 ISO|
|ISO Boost||64 - 25,600 ISO||500 - 102,400 ISO|
|Image Processor||TruePic IX||Dual BIONZ XR|
|Screen Specs||Olympus E-M1 III||Sony A1|
|Viewfinder Type||Electronic viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2360k dots||9437k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1037k dots||1440k dots|
|LCD Attachment||Swivel screen||Tilting screen|
|Shooting Specs||Olympus E-M1 III||Sony A1|
|Focus System||On-Sensor Phase-detect||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/8000s|
|Continuous Shooting||18 shutter flaps/s||10 shutter flaps/s|
|Shutter Life Expectancy||400 000 actuations||500 000 actuations|
|Electronic Shutter||up to 1/32000s||up to 1/32000s|
|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||CFexpress or SDXC cards|
|Second Storage Option||Dual card slots||Dual card slots|
|UHS card support||Single UHS-II||UHS-II|
|Connectivity Specs||Olympus E-M1 III||Sony A1|
|Studio Flash||PC Sync socket||PC Sync socket|
|USB Connector||USB 3.1||USB 3.2|
|HDMI Port||micro HDMI||mini HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||Headphone port||Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Bluetooth Support||Bluetooth built-in||Bluetooth built-in|
|Body Specs||Olympus E-M1 III||Sony A1|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||420 shots per charge||530 shots per charge|
|In-Camera Charging||USB charging||USB charging|
134 x 91 x 69 mm
(5.3 x 3.6 x 2.7 in)
129 x 97 x 81 mm
(5.1 x 3.8 x 3.2 in)
|Camera Weight||580 g (20.5 oz)||737 g (26.0 oz)|
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