Olympus E-620 vs Sony A7

The Olympus E-620 and the Sony Alpha A7 are two digital cameras that were announced, respectively, in February 2009 and October 2013. The E-620 is a DSLR, while the A7 is a mirrorless interchangeable lens camera. The cameras are based on a Four Thirds (E-620) and a full frame (A7) 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-620		Sony A7
Digital single lens reflex		Mirrorless system camera
Four Thirds lenses		Sony E mount lenses
12.2 MP – Four Thirds sensor		24 MP – Full Frame sensor
no Video		1080/60p Video
ISO 100-3,200		ISO 100-25,600 (50 - 51,200)
Optical viewfinder		Electronic viewfinder (2400k dots)
2.7" LCD – 230k dots		3.0" LCD – 1230k dots
Swivel screen (not touch-sensitive)		Tilting screen (no touchscreen)
4 shutter flaps per second		5 shutter flaps per second
In-body stabilization		Lens stabilization only
not weather sealed		Weathersealed body
500 shots per battery charge		340 shots per battery charge
130 x 94 x 60 mm, 521 g		127 x 94 x 48 mm, 474 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus E-620 and the Sony Alpha A7? 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-620 and the Sony A7 is provided 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.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A7 is somewhat smaller (2 percent) than the Olympus E-620. Moreover, the A7 is markedly lighter (9 percent) than the E-620. It is noteworthy in this context that the A7 is splash and dust-proof, while the E-620 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 Four Thirds Lens Catalog (E-620) and the Sony FE Lens Catalog (A7). Mirrorless cameras, such as the A7, have moreover the advantage that they can use many lenses from other systems via adapters, as they have a relatively short flange to focal plane distance.

Concerning battery life, the E-620 gets 500 shots out of its Olympus BLS-1 battery, while the A7 can take 340 images on a single charge of its Sony NP-FW50 power pack. The power pack in the A7 can be charged via the USB port, which can be very convenient when travelling.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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-620	130 mm	94 mm	60 mm	521 g	500	n	Feb 2009	699	ebay.com
2.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	1,699	ebay.com
3.		Olympus E-30	142 mm	108 mm	75 mm	701 g	750	n	Nov 2008	1,299	ebay.com
4.		Olympus E-410	130 mm	91 mm	53 mm	435 g	500	n	Mar 2007	699	ebay.com
5.		Olympus E-420	130 mm	91 mm	53 mm	440 g	500	n	Mar 2008	599	ebay.com
6.		Olympus E-450	130 mm	91 mm	53 mm	440 g	500	n	Mar 2009	499	ebay.com
7.		Olympus E-510	136 mm	92 mm	68 mm	538 g	750	n	Mar 2007	799	ebay.com
8.		Olympus E-520	136 mm	92 mm	68 mm	535 g	750	n	May 2008	699	ebay.com
9.		Olympus E-600	130 mm	94 mm	60 mm	535 g	500	n	Aug 2009	449	ebay.com
10.		Olympus E-P1	121 mm	70 mm	36 mm	355 g	300	n	Jun 2009	799	ebay.com
11.		Olympus E-P2	121 mm	70 mm	36 mm	355 g	300	n	Nov 2009	799	ebay.com
12.		Olympus E-PL1	115 mm	72 mm	42 mm	334 g	290	n	Feb 2010	599	ebay.com
13.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
14.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	2,299	ebay.com
15.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	2,499	ebay.com
16.		Sony RX1	113 mm	65 mm	70 mm	482 g	270	n	Sep 2012	2,799	ebay.com
17.		Sony RX1R	113 mm	65 mm	70 mm	482 g	270	n	Jun 2013	2,799	ebay.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
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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 E-620 was launched at a markedly lower price (by 59 percent) than the A7, 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.

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. 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 Olympus E-620 features a Four Thirds sensor and the Sony A7 a full frame sensor. The sensor area in the A7 is 280 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-620 has a native 4:3 aspect ratio, while the one in the A7 offers a 3:2 aspect.

With 24MP, the A7 offers a higher resolution than the E-620 (12.2MP), but the A7 nevertheless has larger individual pixels (pixel pitch of 5.97μm versus 4.29μm for the E-620) due to its larger sensor. Moreover, the A7 is a much more recent model (by 4 years and 7 months) than the E-620, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units.

The resolution advantage of the Sony A7 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7 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-620 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 A7 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Olympus E-620 has a native sensitivity range from ISO 100 to ISO 3200. The corresponding ISO settings for the Sony Alpha A7 are ISO 100 to ISO 25600, with the possibility to increase the ISO range to 50-51200.

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.

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. Of the two cameras under consideration, the A7 offers substantially better image quality than the E-620 (overall score 35 points higher). The advantage is based on 3.5 bits higher color depth, 3.9 EV in additional dynamic range, and 2.1 stops in additional low light sensitivity. 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-620	Four Thirds	12.2	4032	3024	none	21.3	10.3	536	55
2.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
3.		Olympus E-30	Four Thirds	12.2	4032	3024	none	21.3	10.4	530	55
4.		Olympus E-410	Four Thirds	10.0	3648	2736	none	21.1	10.0	494	51
5.		Olympus E-420	Four Thirds	10.0	3648	2736	none	21.5	10.4	527	56
6.		Olympus E-450	Four Thirds	10.0	3648	2736	none	21.5	10.5	512	56
7.		Olympus E-510	Four Thirds	10.0	3648	2736	none	21.2	10.0	442	52
8.		Olympus E-520	Four Thirds	10.0	3648	2736	none	21.4	10.4	548	55
9.		Olympus E-600	Four Thirds	12.2	4032	3024	none	21.5	10.3	541	55
10.		Olympus E-P1	Four Thirds	12.2	4032	3024	720/30p	21.4	10.4	536	55
11.		Olympus E-P2	Four Thirds	12.2	4032	3024	720/30p	21.5	10.4	505	56
12.		Olympus E-PL1	Four Thirds	12.2	4032	3024	720/30p	21.5	10.1	487	54
13.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
14.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
15.		Sony A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
16.		Sony RX1	Full Frame	24.0	6000	4000	1080/60p	25.1	14.3	2534	93
17.		Sony RX1R	Full Frame	24.0	6000	4000	1080/60p	25.0	13.6	2537	91

Many modern cameras cannot only take still pictures, but also record videos. The A7 indeed provides for movie recording, while the E-620 does not. The highest resolution format that the A7 can use is 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the A7 has an electronic viewfinder (2400k dots), while the E-620 has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The viewfinder in the A7 offers a wider field of view (100%) than the one in the E-620 (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the A7 has a higher magnification (0.71x vs 0.48x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The following table reports on some other key feature differences and similarities of the Olympus E-620, the Sony A7, 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-620	optical	n	2.7 / 230	swivel	n	1/4000s	4.0/s	Y	Y
2.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
3.		Olympus E-30	optical	Y	2.7 / 230	swivel	n	1/8000s	5.0/s	Y	Y
4.		Olympus E-410	optical	n	2.5 / 215	fixed	n	1/4000s	3.0/s	Y	n
5.		Olympus E-420	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	n
6.		Olympus E-450	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	n
7.		Olympus E-510	optical	n	2.5 / 215	fixed	n	1/4000s	3.0/s	Y	Y
8.		Olympus E-520	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	Y
9.		Olympus E-600	optical	n	2.7 / 230	swivel	n	1/4000s	4.0/s	Y	Y
10.		Olympus E-P1	none	n	3.0 / 230	fixed	n	1/4000s	3.0/s	n	Y
11.		Olympus E-P2	optional	n	3.0 / 230	fixed	n	1/4000s	3.0/s	n	Y
12.		Olympus E-PL1	optional	n	2.7 / 230	fixed	n	1/2000s	3.0/s	Y	Y
13.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
14.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
15.		Sony A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
16.		Sony RX1	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
17.		Sony RX1R	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
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-620 has one, while the A7 does not. While the built-in flash of the E-620 is not very powerful, it can at times be useful as a fill-in light.

The E-620 writes its imaging data to Compact Flash or xD Picture cards, while the A7 uses SDXC or Memory Stick PRO Duo cards. The E-620 features dual card slots, which can be very useful in case a memory card fails. In contrast, the A7 only has one slot.

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 E-620 and Sony Alpha A7 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-620	Y	- / -	-	-	-	2.0	-	-	-
2.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
3.		Olympus E-30	Y	- / -	-	-	-	2.0	-	-	-
4.		Olympus E-410	Y	- / -	-	-	-	2.0	-	-	-
5.		Olympus E-420	Y	- / -	-	-	-	2.0	-	-	-
6.		Olympus E-450	Y	- / -	-	-	-	2.0	-	-	-
7.		Olympus E-510	Y	- / -	-	-	-	2.0	-	-	-
8.		Olympus E-520	Y	- / -	-	-	-	2.0	-	-	-
9.		Olympus E-600	Y	- / -	-	-	-	2.0	-	-	-
10.		Olympus E-P1	Y	stereo / -	-	-	mini	2.0	-	-	-
11.		Olympus E-P2	Y	stereo / -	-	-	mini	2.0	-	-	-
12.		Olympus E-PL1	Y	stereo / -	-	-	mini	2.0	-	-	-
13.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
14.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
15.		Sony A7S	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
16.		Sony RX1	Y	stereo / mono	Y	-	mini	2.0	-	-	-
17.		Sony RX1R	Y	stereo / mono	Y	-	mini	2.0	-	-	-

It is notable that the A7 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the E-620 does not provide wifi capability.

Both the E-620 and the A7 have been discontinued, but can regularly be found used on ebay. The E-620 was replaced by the Olympus E-600, while the A7 was followed by the Sony A7 II. Further information on the features and operation of the E-620 and A7 can be found, respectively, in the Olympus E-620 Manual (free pdf) or the online Sony A7 Manual.

Review summary

So how do things add up? Is the Olympus E-620 better than the Sony A7 or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Reasons to prefer the Olympus E-620:

• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• 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.
• Longer lasting: Can take more shots (500 versus 340) on a single battery charge.
• Sharper images: Has hand-shake reducing image stabilization built-in.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• More affordable: Was introduced into a lower priced category (59 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in February 2009).

Arguments in favor of the Sony Alpha A7:

• More detail: Has more megapixels (24 vs 12.2MP), which boosts linear resolution by 43%.
• Better image quality: Scores substantially higher (35 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (3.5 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (3.9 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (2.1 stops ISO advantage).
• Broader imaging potential: Can capture not only stills but also 1080/60p video.
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• More framing info: Has an electronic viewfinder that displays shooting data.
• More complete view: Has a viewfinder with a larger field of view (100% vs 95%).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.71x vs 0.48x).
• Larger screen: Has a bigger rear LCD (3.0" vs 2.7") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (1230k vs 230k dots).
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (5 vs 4 flaps/sec) to capture the decisive moment.
• Easier travel charging: Can be conveniently charged via its USB port.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• More modern: Reflects 4 years and 7 months of technical progress since the E-620 launch.

If the number of relative strengths (bullet points above) is taken as a guide, the A7 is the clear winner of the contest (20 : 9 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-620 and the Sony A7 place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Mirrorless Interchangeable Lens 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 says little about, for example, the shooting experience and imaging performance of the E-620 and the A7 in practical situations. 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 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-620	3/5	88/100	..	72/100	4.5/5	5/5	Feb 2009	699	ebay.com
2.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	1,699	ebay.com
3.		Olympus E-30	..	..	..	71/100	4.5/5	4/5	Nov 2008	1,299	ebay.com
4.		Olympus E-410	..	86/100	..	+ +	4/5	4.5/5	Mar 2007	699	ebay.com
5.		Olympus E-420	..	85/100	..	+ +	4/5	4.5/5	Mar 2008	599	ebay.com
6.		Olympus E-450	..	..	..	..	4/5	4/5	Mar 2009	499	ebay.com
7.		Olympus E-510	..	89/100	..	+ +	3.5/5	4.5/5	Mar 2007	799	ebay.com
8.		Olympus E-520	..	87/100	..	+ +	4.5/5	4.5/5	May 2008	699	ebay.com
9.		Olympus E-600	..	..	..	..	..	4.5/5	Aug 2009	449	ebay.com
10.		Olympus E-P1	..	+	..	66/100	4/5	4.5/5	Jun 2009	799	ebay.com
11.		Olympus E-P2	3/5	+	..	69/100	4/5	4.5/5	Nov 2009	799	ebay.com
12.		Olympus E-PL1	..	86/100	..	69/100	4/5	4.5/5	Feb 2010	599	ebay.com
13.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
14.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	2,299	ebay.com
15.		Sony A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	2,499	ebay.com
16.		Sony RX1	5/5	..	..	79/100	4/5	4.5/5	Sep 2012	2,799	ebay.com
17.		Sony RX1R	5/5	..	..	..	4/5	4.5/5	Jun 2013	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 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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