Olympus E-P7 vs Sony A7 III

The Olympus PEN E-P7 and the Sony Alpha A7 III are two enthusiast cameras that were revealed to the public, respectively, in June 2021 and February 2018. Both the E-P7 and the A7 III are mirrorless interchangeable lens cameras that are based on a Four Thirds (E-P7) and a full frame (A7 III) sensor. The Olympus 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.

Headline Specifications

Olympus E-P7		Sony A7 III
Mirrorless system camera		Mirrorless system camera
Micro Four Thirds lenses		Sony E mount lenses
20.2 MP – Four Thirds sensor		24 MP – Full Frame sensor
4K/30p Video		4K/30p Video
ISO 200-25,600		ISO 100-51,200 (50 - 204,800)
No viewfinder, LCD framing		Electronic viewfinder (2359k dots)
3.0" LCD – 1040k dots		3.0" LCD – 922k dots
Tilting touchscreen		Tilting touchscreen
8.7 shutter flaps per second		10 shutter flaps per second
In-body stabilization		In-body stabilization
not weather sealed		Weathersealed body
360 shots per battery charge		610 shots per battery charge
118 x 69 x 38 mm, 337 g		127 x 96 x 74 mm, 650 g

Check E-P7 price at
amazon.com
Check A7 III price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus PEN E-P7 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.

Body comparison

An illustration of the physical size and weight of the Olympus E-P7 and the Sony A7 III is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive views from the front, the top, and the rear side are shown. All size dimensions are rounded to the nearest millimeter.

The E-P7 can be obtained in three different colors (black, silver, white), while the A7 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 A7 III is considerably larger (50 percent) than the Olympus E-P7. Moreover, the A7 III is substantially heavier (93 percent) than the E-P7. It is noteworthy in this context that the A7 III is splash and dust-proof, while the E-P7 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 (E-P7) 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 E-P7 gets 360 shots out of its Olympus BLS-50 battery, while the A7 III can take 610 images on a single charge of its Sony NP-FZ100 power pack. The power pack in the A7 III can be charged via the USB port, 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.

Body Specifications

#		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price (USD)	Street Price
1.		Olympus E-P7	118 mm	69 mm	38 mm	337 g	360	n	Jun 2021	799	amazon.com
2.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	1,999	amazon.com
3.		Nikon Z6	134 mm	101 mm	67 mm	675 g	310	Y	Aug 2018	1,999	ebay.com
4.		Olympus E-M10 IV	122 mm	84 mm	49 mm	383 g	360	n	Aug 2020	699	amazon.com
5.		Olympus E-M10 III	122 mm	84 mm	50 mm	410 g	330	n	Aug 2017	649	ebay.com
6.		Olympus PEN-F	125 mm	72 mm	37 mm	427 g	330	n	Jan 2016	1,199	ebay.com
7.		Olympus E-M10 II	120 mm	83 mm	47 mm	390 g	320	n	Aug 2015	649	ebay.com
8.		Olympus E-M10	119 mm	82 mm	46 mm	396 g	320	n	Jan 2014	699	ebay.com
9.		Olympus E-P5	122 mm	69 mm	37 mm	420 g	330	n	May 2013	999	ebay.com
10.		Olympus E-P3	122 mm	69 mm	34 mm	369 g	330	n	Jun 2011	799	ebay.com
11.		Olympus E-P1	121 mm	70 mm	36 mm	355 g	300	n	Jun 2009	799	ebay.com
12.		Olympus E-P2	121 mm	70 mm	36 mm	355 g	300	n	Nov 2009	799	ebay.com
13.		Panasonic GX9	124 mm	72 mm	47 mm	407 g	260	n	Feb 2018	849	ebay.com
14.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	3,499	ebay.com
15.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	3,199	ebay.com
16.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499	ebay.com
17.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
Convert to Imperial

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-P7 was launched at a markedly lower price (by 60 percent) than the A7 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.

Sensor comparison

The size of the sensor inside a digital camera is one of the key determinants of image quality. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Olympus E-P7 features a Four Thirds sensor and the Sony A7 III a full frame sensor. The sensor area in the A7 III is 275 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-P7 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 E-P7 (20.2MP), but the A7 III nevertheless has larger individual pixels (pixel pitch of 5.94μm versus 3.34μm for the E-P7) due to its larger sensor. However, the E-P7 is a much more recent model (by 3 years and 3 months) than the A7 III, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units.

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 Olympus E-P7 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.

The Olympus PEN E-P7 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.

In terms of underlying technology, the E-P7 is build around a CMOS sensor, while the A7 III uses a BSI-CMOS imager. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

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.

Sensor Characteristics

#		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Olympus E-P7	Four Thirds	20.2	5184	3888	4K/30p	23.4	13.3	1494	77
2.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
3.		Nikon Z6	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	3299	95
4.		Olympus E-M10 IV	Four Thirds	20.2	5184	3888	4K/30p	23.3	13.2	1402	76
5.		Olympus E-M10 III	Four Thirds	15.9	4608	3456	4K/30p	23.1	12.8	1120	74
6.		Olympus PEN-F	Four Thirds	20.2	5184	3888	1080/60p	23.1	12.4	894	74
7.		Olympus E-M10 II	Four Thirds	15.9	4608	3456	1080/60p	23.1	12.5	842	73
8.		Olympus E-M10	Four Thirds	15.9	4608	3456	1080/30p	22.8	12.3	884	72
9.		Olympus E-P5	Four Thirds	15.9	4608	3456	1080/30p	22.8	12.4	895	72
10.		Olympus E-P3	Four Thirds	12.2	4032	3024	1080/60i	20.8	10.1	536	51
11.		Olympus E-P1	Four Thirds	12.2	4032	3024	720/30p	21.4	10.4	536	55
12.		Olympus E-P2	Four Thirds	12.2	4032	3024	720/30p	21.5	10.4	505	56
13.		Panasonic GX9	Four Thirds	20.2	5184	3888	4K/30p	23.1	12.8	1163	74
14.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
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 A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
Note: DXO values in italics represent estimates based on sensor size and age.

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, and both provide the same movie specifications (4K/30p).

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the A7 III has an electronic viewfinder (2359k dots), which can be very helpful when shooting in bright sunlight. In contrast, the E-P7 relies on live view and the rear LCD for framing. The table below summarizes some of the other core capabilities of the Olympus E-P7 and Sony A7 III in connection with corresponding information for a sample of similar cameras.

Core Features

#		Camera Model	Viewfinder (Type or 000 dots)	Control Panel (yes/no)	LCD Specifications (inch/000 dots)	LCD Attach- ment	Touch Screen (yes/no)	Max Shutter Speed *	Max Shutter Flaps *	Built-in Flash (yes/no)	Built-in Image Stab
1.		Olympus E-P7	none	n	3.0 / 1040	tilting	Y	1/4000s	8.7/s	Y	Y
2.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
3.		Nikon Z6	3690	Y	3.2 / 2100	tilting	Y	1/8000s	12.0/s	n	Y
4.		Olympus E-M10 IV	2360	n	3.0 / 1040	tilting	Y	1/4000s	15.0/s	Y	Y
5.		Olympus E-M10 III	2360	n	3.0 / 1040	tilting	Y	1/4000s	8.6/s	Y	Y
6.		Olympus PEN-F	2360	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
7.		Olympus E-M10 II	2360	n	3.0 / 1040	tilting	Y	1/4000s	8.0/s	Y	Y
8.		Olympus E-M10	1440	n	3.0 / 1037	tilting	Y	1/4000s	8.0/s	Y	Y
9.		Olympus E-P5	optional	n	3.0 / 1037	tilting	Y	1/8000s	9.0/s	Y	Y
10.		Olympus E-P3	optional	n	3.0 / 614	fixed	Y	1/4000s	3.0/s	Y	Y
11.		Olympus E-P1	none	n	3.0 / 230	fixed	n	1/4000s	3.0/s	n	Y
12.		Olympus E-P2	optional	n	3.0 / 230	fixed	n	1/4000s	3.0/s	n	Y
13.		Panasonic GX9	2760	n	3.0 / 1240	tilting	Y	1/4000s	9.0/s	Y	Y
14.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
15.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
16.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
17.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One difference between the cameras concerns the presence of an on-board flash. The E-P7 has one, while the A7 III does not. While the built-in flash of the E-P7 is not very powerful, it can at times be useful as a fill-in light.

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-P7 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 E-P7 writes its imaging data to SDXC cards, while the A7 III uses SDXC or Memory Stick PRO Duo cards. The A7 III features dual card slots, which can be very useful in case a memory card fails. In contrast, the E-P7 only has one slot. Both the E-P7 and the A7 III support UHS-II cards, which provide for Ultra High Speed data transfer of up to 312 MB/s (the second slot of the A7 III only offers slower UHS-I transfer rates, though).

Connectivity comparison

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 PEN E-P7 and Sony Alpha A7 III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.

Input-Output Connections

#		Camera Model	Hotshoe Port	Internal Mic / Speaker	Microphone Port	Headphone Port	HDMI Port	USB Port	WiFi Support	NFC Support	Bluetooth Support
1.		Olympus E-P7	Y	stereo / mono	-	-	micro	2.0	Y	-	Y
2.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
3.		Nikon Z6	Y	stereo / mono	Y	Y	micro	3.1	Y	-	Y
4.		Olympus E-M10 IV	Y	stereo / mono	-	-	micro	2.0	Y	-	Y
5.		Olympus E-M10 III	Y	stereo / mono	-	-	micro	2.0	Y	-	-
6.		Olympus PEN-F	Y	stereo / mono	-	-	micro	2.0	Y	-	-
7.		Olympus E-M10 II	Y	stereo / mono	-	-	micro	2.0	Y	-	-
8.		Olympus E-M10	Y	stereo / mono	-	-	micro	2.0	Y	-	-
9.		Olympus E-P5	Y	stereo / mono	-	-	micro	2.0	Y	-	-
10.		Olympus E-P3	Y	stereo / -	-	-	mini	2.0	-	-	-
11.		Olympus E-P1	Y	stereo / -	-	-	mini	2.0	-	-	-
12.		Olympus E-P2	Y	stereo / -	-	-	mini	2.0	-	-	-
13.		Panasonic GX9	Y	stereo / mono	-	-	micro	2.0	Y	-	Y
14.		Sony A7R IV	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
16.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
17.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-

It is notable that the A7 III has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The E-P7 lacks such a headphone port.

Both the E-P7 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 E-P7 followed on from the Olympus E-P5. Further information on the features and operation of the E-P7 and A7 III can be found, respectively, in the Olympus E-P7 Manual (free pdf) or the online Sony A7 III Manual.

Review summary

So how do things add up? Is the Olympus E-P7 better than the Sony A7 III or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Reasons to prefer the Olympus PEN E-P7:

• More detailed LCD: Has a higher resolution rear screen (1040k vs 922k dots).
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• More compact: Is smaller (118x69mm vs 127x96mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 313g or 48 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 (60 percent cheaper at launch).
• More modern: Reflects 3 years and 3 months of technical progress since the A7 III launch.

Advantages of the Sony Alpha A7 III:

• More detail: Has more megapixels (24 vs 20.2MP), which boosts linear resolution by 11%.
• 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.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (10 vs 8.7 flaps/sec) to capture the decisive moment.
• Longer lasting: Gets more shots (610 versus 360) 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.
• Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• More heavily discounted: Has been around for much longer (launched in February 2018).

If the number of relative strengths (bullet points above) is taken as a guide, the A7 III is the clear winner of the contest (14 : 7 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 sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape 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-P7 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it says little about, for example, the shooting experience and imaging performance of the E-P7 and the A7 III in practical situations. 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.

Expert reviews

This is why hands-on reviews by experts are important. The adjacent summary-table relays the overall verdicts of several of the most popular camera review sites (amateurphotographer [AP], cameralabs [CL], digitalcameraworld [DCW], 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.

Expert Camera Reviews

#		Camera   Model	AP   score	CL   score	DCW   score	DPR   score	EPZ   score	PB   score	Camera Launch	Launch Price (USD)	Street Price
1.		Olympus E-P7	4/5	..	4.5/5	..	..	4.5/5	Jun 2021	799	amazon.com
2.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	1,999	amazon.com
3.		Nikon Z6	5/5	..	5/5	89/100	4.5/5	5/5	Aug 2018	1,999	ebay.com
4.		Olympus E-M10 IV	4.5/5	..	5/5	81/100	4.5/5	4.5/5	Aug 2020	699	amazon.com
5.		Olympus E-M10 III	..	+	5/5	80/100	4.5/5	4.5/5	Aug 2017	649	ebay.com
6.		Olympus PEN-F	..	..	4/5	82/100	4.5/5	5/5	Jan 2016	1,199	ebay.com
7.		Olympus E-M10 II	4.5/5	+ +	..	80/100	5/5	5/5	Aug 2015	649	ebay.com
8.		Olympus E-M10	4/5	..	..	80/100	5/5	5/5	Jan 2014	699	ebay.com
9.		Olympus E-P5	5/5	+ +	..	78/100	4.5/5	5/5	May 2013	999	ebay.com
10.		Olympus E-P3	..	83/100	..	74/100	4.5/5	4.5/5	Jun 2011	799	ebay.com
11.		Olympus E-P1	..	+	..	66/100	4/5	4.5/5	Jun 2009	799	ebay.com
12.		Olympus E-P2	3/5	+	..	69/100	4/5	4.5/5	Nov 2009	799	ebay.com
13.		Panasonic GX9	4/5	+	4/5	84/100	4.5/5	4.5/5	Feb 2018	849	ebay.com
14.		Sony A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	3,499	ebay.com
15.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	3,199	ebay.com
16.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	4,499	ebay.com
17.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. It should also be noted that some of the review sites have over time altered the way they render their verdicts.

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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 a corresponding selection in the search boxes below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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