Olympus E-P3 vs Sony A77

The Olympus PEN E-P3 and the Sony Alpha SLT-A77 are two enthusiast cameras that were revealed to the public, respectively, in June 2011 and August 2011. The E-P3 is a mirrorless interchangeable lens camera, while the A77 is a DSLR. The cameras are based on a Four Thirds (E-P3) and an APS-C (A77) sensor. The Olympus has a resolution of 12.2 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-P3		Sony A77
Mirrorless system camera		Digital single lens reflex
Micro Four Thirds lenses		Sony A mount lenses
12.2 MP – Four Thirds sensor		24 MP – APS-C sensor
1080/60i Video		1080/60p Video
ISO 200-12,800		ISO 100-16,000 (50 - 25,600)
Viewfinder optional		Electronic viewfinder (2359k dots)
3.0" LCD – 614k dots		3.0" LCD – 921k dots
Fixed touchscreen		Fully flexible screen (no touchscreen)
3 shutter flaps per second		12 shutter flaps per second
In-body stabilization		In-body stabilization
not weather sealed		Weathersealed body
330 shots per battery charge		470 shots per battery charge
122 x 69 x 34 mm, 369 g		143 x 104 x 81 mm, 732 g

Check E-P3 offers at
ebay.com
Check A77 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus PEN E-P3 and the Sony Alpha SLT-A77? 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

The physical size and weight of the Olympus E-P3 and the Sony A77 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 dimensions are rounded to the nearest millimeter.

The E-P3 can be obtained in three different colors (black, silver, white), while the A77 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 A77 is considerably larger (77 percent) than the Olympus E-P3. Moreover, the A77 is substantially heavier (98 percent) than the E-P3. It is noteworthy in this context that the A77 is splash and dust-proof, while the E-P3 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. Hence, you might want to study and compare the specifications of available lenses in order to get the full picture of the size and weight of the two camera systems.

Concerning battery life, the E-P3 gets 330 shots out of its Olympus BLS-5 battery, while the A77 can take 470 images on a single charge of its Sony NP-FM500H power pack.

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-P3	122 mm	69 mm	34 mm	369 g	330	n	Jun 2011	799	ebay.com
2.		Sony A77	143 mm	104 mm	81 mm	732 g	470	Y	Aug 2011	1,399	ebay.com
3.		Olympus E-P5	122 mm	69 mm	37 mm	420 g	330	n	May 2013	999	ebay.com
4.		Olympus E-PL5	111 mm	64 mm	38 mm	325 g	360	n	Sep 2012	599	ebay.com
5.		Olympus E-PL2	114 mm	72 mm	42 mm	362 g	280	n	Jan 2011	599	ebay.com
6.		Olympus E-PL3	110 mm	64 mm	37 mm	313 g	300	n	Jun 2011	599	ebay.com
7.		Olympus E-PM1	110 mm	64 mm	34 mm	265 g	330	n	Jun 2011	499	ebay.com
8.		Olympus E-PL1	115 mm	72 mm	42 mm	334 g	290	n	Feb 2010	599	ebay.com
9.		Olympus E-P1	121 mm	70 mm	36 mm	355 g	300	n	Jun 2009	799	ebay.com
10.		Olympus E-P2	121 mm	70 mm	36 mm	355 g	300	n	Nov 2009	799	ebay.com
11.		Panasonic GX1	116 mm	68 mm	39 mm	318 g	320	n	Nov 2011	699	ebay.com
12.		Panasonic G10	124 mm	84 mm	74 mm	388 g	380	n	Mar 2010	499	ebay.com
13.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
14.		Sony A6500	120 mm	67 mm	53 mm	453 g	350	Y	Oct 2016	1,399	ebay.com
15.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
16.		Sony A77 II	143 mm	104 mm	81 mm	647 g	480	Y	May 2014	1,199	ebay.com
17.		Sony A99	147 mm	111 mm	78 mm	812 g	500	Y	Sep 2012	2,799	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

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 E-P3 was launched at a markedly lower price (by 43 percent) than the A77, 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 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 tend to be associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Olympus E-P3 features a Four Thirds sensor and the Sony A77 an APS-C sensor. The sensor area in the A77 is 63 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.5. The sensor in the E-P3 has a native 4:3 aspect ratio, while the one in the A77 offers a 3:2 aspect.

With 24MP, the A77 offers a higher resolution than the E-P3 (12.2MP), but the A77 has smaller individual pixels (pixel pitch of 3.91μm versus 4.29μm for the E-P3). It is noteworthy in this context that the two cameras were released in close succession, so that their sensors are from the same technological generation.

The resolution advantage of the Sony A77 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A77 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-P3 are 20.2 x 15.1 inches or 51.2 x 38.4 cm for good quality, 16.1 x 12.1 inches or 41 x 30.7 cm for very good quality, and 13.4 x 10.1 inches or 34.1 x 25.6 cm for excellent quality prints.

The Olympus PEN E-P3 has a native sensitivity range from ISO 200 to ISO 12800. The corresponding ISO settings for the Sony Alpha SLT-A77 are ISO 100 to ISO 16000, with the possibility to increase the ISO range to 50-25600.

Technology-wise, both cameras are equipped with CMOS (Complementary Metal–Oxide–Semiconductor) sensors. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

For many cameras, data on sensor performance has been reported by DXO Mark. This service determines an overall sensor rating, as well as sub-scores for low-light sensitivity ("DXO Sports"), dynamic range ("DXO Landscape"), and color depth ("DXO Portrait"). Of the two cameras under consideration, the A77 offers substantially better image quality than the E-P3 (overall score 27 points higher). The advantage is based on 3.2 bits higher color depth, 3.1 EV in additional dynamic range, and 0.6 stops in additional low light sensitivity. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.

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-P3	Four Thirds	12.2	4032	3024	1080/60i	20.8	10.1	536	51
2.		Sony A77	APS-C	24.0	6000	4000	1080/60p	24.0	13.2	801	78
3.		Olympus E-P5	Four Thirds	15.9	4608	3456	1080/30p	22.8	12.4	895	72
4.		Olympus E-PL5	Four Thirds	15.9	4608	3456	1080/30p	22.8	12.3	889	72
5.		Olympus E-PL2	Four Thirds	12.2	4032	3024	720/30p	21.4	10.2	573	55
6.		Olympus E-PL3	Four Thirds	12.2	4032	3024	1080/60i	20.9	10.3	499	52
7.		Olympus E-PM1	Four Thirds	12.2	4032	3024	1080/60i	21.0	10.3	499	52
8.		Olympus E-PL1	Four Thirds	12.2	4032	3024	720/30p	21.5	10.1	487	54
9.		Olympus E-P1	Four Thirds	12.2	4032	3024	720/30p	21.4	10.4	536	55
10.		Olympus E-P2	Four Thirds	12.2	4032	3024	720/30p	21.5	10.4	505	56
11.		Panasonic GX1	Four Thirds	15.8	4592	3448	1080/60p	20.8	10.6	703	55
12.		Panasonic G10	Four Thirds	12.0	4000	3000	720/30p	21.2	10.1	411	52
13.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
14.		Sony A6500	APS-C	24.0	6000	4000	4K/30p	24.5	13.7	1405	85
15.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
16.		Sony A77 II	APS-C	24.0	6000	4000	1080/60p	24.4	13.4	1013	82
17.		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, but the A77 provides a faster frame rate than the E-P3. It can shoot movie footage at 1080/60p, while the Olympus is limited to 1080/60i.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A77 has an electronic viewfinder (2359k dots), which can be very helpful when shooting in bright sunlight. In contrast, the E-P3 relies on live view and the rear LCD for framing. That said, the E-P3 can be equipped with an optional viewfinder – the VF-3. The following table reports on some other key feature differences and similarities of the Olympus E-P3, the Sony A77, and comparable 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-P3	optional	n	3.0 / 614	fixed	Y	1/4000s	3.0/s	Y	Y
2.		Sony A77	2359	Y	3.0 / 921	full-flex	n	1/8000s	12.0/s	Y	Y
3.		Olympus E-P5	optional	n	3.0 / 1037	tilting	Y	1/8000s	9.0/s	Y	Y
4.		Olympus E-PL5	optional	n	3.0 / 460	tilting	Y	1/4000s	8.0/s	n	Y
5.		Olympus E-PL2	optional	n	3.0 / 460	fixed	n	1/4000s	3.0/s	Y	Y
6.		Olympus E-PL3	optional	n	3.0 / 460	tilting	n	1/4000s	5.5/s	n	Y
7.		Olympus E-PM1	optional	n	3.0 / 460	fixed	n	1/4000s	5.5/s	n	Y
8.		Olympus E-PL1	optional	n	2.7 / 230	fixed	n	1/2000s	3.0/s	Y	Y
9.		Olympus E-P1	none	n	3.0 / 230	fixed	n	1/4000s	3.0/s	n	Y
10.		Olympus E-P2	optional	n	3.0 / 230	fixed	n	1/4000s	3.0/s	n	Y
11.		Panasonic GX1	optional	n	3.0 / 460	fixed	Y	1/4000s	4.2/s	Y	n
12.		Panasonic G10	202	n	3.0 / 460	fixed	n	1/4000s	2.6/s	Y	n
13.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
14.		Sony A6500	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	Y
15.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
16.		Sony A77 II	2359	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	Y	Y
17.		Sony A99	2359	Y	3.0 / 1229	full-flex	n	1/8000s	6.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The E-P3 has a touchscreen, while the A77 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

The E-P3 writes its imaging data to SDXC cards, while the A77 uses SDXC or Memory Stick PRO Duo cards. Both cameras can use UHS-I cards, which provide for Ultra High Speed data transfer of up to 104 MB/s.

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-P3 and Sony Alpha SLT-A77 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-P3	Y	stereo / -	-	-	mini	2.0	-	-	-
2.		Sony A77	Y	stereo / mono	Y	-	mini	2.0	-	-	-
3.		Olympus E-P5	Y	stereo / mono	-	-	micro	2.0	Y	-	-
4.		Olympus E-PL5	Y	stereo / mono	-	-	mini	2.0	-	-	-
5.		Olympus E-PL2	Y	stereo / -	-	-	mini	2.0	-	-	-
6.		Olympus E-PL3	Y	stereo / -	-	-	mini	2.0	-	-	-
7.		Olympus E-PM1	Y	stereo / mono	-	-	mini	2.0	-	-	-
8.		Olympus E-PL1	Y	stereo / -	-	-	mini	2.0	-	-	-
9.		Olympus E-P1	Y	stereo / -	-	-	mini	2.0	-	-	-
10.		Olympus E-P2	Y	stereo / -	-	-	mini	2.0	-	-	-
11.		Panasonic GX1	Y	stereo / mono	-	-	mini	2.0	-	-	-
12.		Panasonic G10	Y	mono / -	-	-	mini	2.0	-	-	-
13.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
14.		Sony A6500	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
15.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
16.		Sony A77 II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
17.		Sony A99	Y	stereo / mono	Y	Y	mini	2.0	-	-	-

It is notable that the A77 has a microphone port, which can help to improve the quality of audio recordings by attaching an external microphone. The E-P3 does not feature such a mic input.

Studio photographers will appreciate that the Sony A77 (unlike the E-P3) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Travel and landscape photographers will find it useful that the A77 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the E-P3 and the A77 have been discontinued, but can regularly be found used on ebay. The E-P3 was replaced by the Olympus E-P5, while the A77 was followed by the Sony A77 II. Further information on the features and operation of the E-P3 and A77 can be found, respectively, in the Olympus E-P3 Manual (free pdf) or the online Sony A77 Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Olympus E-P3 or the Sony A77 – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.

Arguments in favor of the Olympus PEN E-P3:

• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• More compact: Is smaller (122x69mm vs 143x104mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 363g or 50 percent) and hence easier to carry around.
• More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
• More affordable: Was introduced into a lower priced category (43 percent cheaper at launch).

Reasons to prefer the Sony Alpha SLT-A77:

• More detail: Has more megapixels (24 vs 12.2MP), which boosts linear resolution by 43%.
• Better image quality: Scores substantially higher (27 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (3.2 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (3.1 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (0.6 stops ISO advantage).
• Better video: Provides higher movie framerates (1080/60p versus 1080/60i).
• Better sound: Can connect to an external microphone for higher quality sound recording.
• Easier framing: Has an electronic viewfinder for image composition and settings control.
• Easier setting verification: Features a control panel on top to check shooting parameters.
• More detailed LCD: Has a higher resolution rear screen (921k vs 614k dots).
• More flexible LCD: Has a full-flex 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 shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (12 vs 3 flaps/sec) to capture the decisive moment.
• Longer lasting: Gets more shots (470 versus 330) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.

If the count of relative strengths (bullet points above) is taken as a measure, the A77 is the clear winner of the contest (18 : 5 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. 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-P3 and the Sony A77 place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera and Best DSLR Camera listings 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 E-P3 or the A77 perform in practice. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate.

Expert reviews

This is where reviews by experts come in. The following table reports the overall ratings of the cameras as published by some of the major 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-P3	..	83/100	..	74/100	4.5/5	4.5/5	Jun 2011	799	ebay.com
2.		Sony A77	5/5	91/100	..	81/100	..	5/5	Aug 2011	1,399	ebay.com
3.		Olympus E-P5	5/5	+ +	..	78/100	4.5/5	5/5	May 2013	999	ebay.com
4.		Olympus E-PL5	3/5	+ +	..	..	4.5/5	4.5/5	Sep 2012	599	ebay.com
5.		Olympus E-PL2	3/5	83/100	..	71/100	4.5/5	4.5/5	Jan 2011	599	ebay.com
6.		Olympus E-PL3	3/5	+ +	..	72/100	4.5/5	4/5	Jun 2011	599	ebay.com
7.		Olympus E-PM1	..	86/100	..	71/100	4.5/5	4.5/5	Jun 2011	499	ebay.com
8.		Olympus E-PL1	..	86/100	..	69/100	4/5	4.5/5	Feb 2010	599	ebay.com
9.		Olympus E-P1	..	+	..	66/100	4/5	4.5/5	Jun 2009	799	ebay.com
10.		Olympus E-P2	3/5	+	..	69/100	4/5	4.5/5	Nov 2009	799	ebay.com
11.		Panasonic GX1	3/5	+	..	77/100	4.5/5	4.5/5	Nov 2011	699	ebay.com
12.		Panasonic G10	3/5	..	..	70/100	4/5	4/5	Mar 2010	499	ebay.com
13.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
14.		Sony A6500	5/5	+ +	3.5/5	85/100	4.5/5	4.5/5	Oct 2016	1,399	ebay.com
15.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
16.		Sony A77 II	4/5	..	..	80/100	4.5/5	5/5	May 2014	1,199	ebay.com
17.		Sony A99	5/5	..	..	84/100	4.5/5	4.5/5	Sep 2012	2,799	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted 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. Hence, a score should always be seen in the context of the camera's market launch date and its price, 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.

Check E-P3 offers at
ebay.com
Check A77 offers at
ebay.com

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. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

~

Check E-P3 offers at
ebay.com
Check A77 offers at
ebay.com

Did you notice an error on this page? If so, please get in touch, so that we can correct the information.