Olympus E-3 vs Sony A7

The Olympus E-3 and the Sony Alpha A7 are two digital cameras that were officially introduced, respectively, in October 2007 and October 2013. The E-3 is a DSLR, while the A7 is a mirrorless interchangeable lens camera. The cameras are based on a Four Thirds (E-3) and a full frame (A7) sensor. The Olympus has a resolution of 10 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-3		Sony A7
Digital single lens reflex		Mirrorless system camera
Four Thirds lenses		Sony E mount lenses
10 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)
2.5" LCD – 230k dots		3.0" LCD – 1230k dots
Swivel screen (not touch-sensitive)		Tilting screen (no touchscreen)
5 shutter flaps per second		5 shutter flaps per second
In-body stabilization		Lens stabilization only
Weathersealed body		Weathersealed body
750 shots per battery charge		340 shots per battery charge
142 x 116 x 75 mm, 876 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-3 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-3 and the Sony A7 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 measures 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 notably smaller (28 percent) than the Olympus E-3. Moreover, the A7 is substantially lighter (46 percent) than the E-3. 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 Four Thirds Lens Catalog (E-3) 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-3 gets 750 shots out of its Olympus BLM-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. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price	Street Price
1.		Olympus E-3	142 mm	116 mm	75 mm	876 g	750	Y	Oct 2007	US$ 1 699	ebay.com
2.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	US$ 1 699	ebay.com
3.		Nikon D300	147 mm	114 mm	74 mm	925 g	1000	Y	Aug 2007	US$ 1 799	ebay.com
4.		Olympus E-1	141 mm	104 mm	81 mm	738 g	750	Y	Jun 2003	US$ 1 699	ebay.com
5.		Olympus E-5	142 mm	117 mm	75 mm	873 g	750	Y	Sep 2010	US$ 1 699	ebay.com
6.		Olympus E-30	142 mm	108 mm	75 mm	701 g	750	n	Nov 2008	US$ 1 299	ebay.com
7.		Olympus E-410	130 mm	91 mm	53 mm	435 g	500	n	Mar 2007	US$ 699	ebay.com
8.		Olympus E-420	130 mm	91 mm	53 mm	440 g	500	n	Mar 2008	US$ 599	ebay.com
9.		Olympus E-510	136 mm	92 mm	68 mm	538 g	750	n	Mar 2007	US$ 799	ebay.com
10.		Olympus E-520	136 mm	92 mm	68 mm	535 g	750	n	May 2008	US$ 699	ebay.com
11.		Olympus E-600	130 mm	94 mm	60 mm	535 g	500	n	Aug 2009	US$ 449	ebay.com
12.		Olympus E-620	130 mm	94 mm	60 mm	521 g	500	n	Feb 2009	US$ 699	ebay.com
13.		Samsung NX1	139 mm	102 mm	66 mm	550 g	500	Y	Sep 2014	US$ 1 499	ebay.com
14.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	US$ 1 999	ebay.com
15.		Sony A7C	124 mm	71 mm	60 mm	509 g	740	Y	Sep 2020	US$ 1 799	amazon.com
16.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	US$ 2 299	ebay.com
17.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	US$ 2 499	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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The two cameras under review were launched at the same price and fall into the same 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

The size of the imaging sensor is a crucial determinant 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. 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 associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Olympus E-3 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-3 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-3 (10MP), but the A7 nevertheless has larger individual pixels (pixel pitch of 5.97μm versus 4.74μm for the E-3) due to its larger sensor. Moreover, the A7 is a much more recent model (by 6 years) than the E-3, 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-3 are 18.2 x 13.7 inches or 46.3 x 34.7 cm for good quality, 14.6 x 10.9 inches or 37.1 x 27.8 cm for very good quality, and 12.2 x 9.1 inches or 30.9 x 23.2 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-3 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.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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 A7 offers substantially better image quality than the E-3 (overall score 34 points higher). The advantage is based on 3.2 bits higher color depth, 3.7 EV in additional dynamic range, and 2 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-3	Four Thirds	10.0	3648	2736	none	21.6	10.5	571	56
2.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
3.		Nikon D300	APS-C	12.2	4288	2848	none	22.1	12.0	679	67
4.		Olympus E-1	Four Thirds	4.9	2560	1920	none	20.0	9.7	-145	44
5.		Olympus E-5	Four Thirds	12.2	4032	3024	720/30p	21.6	10.5	519	56
6.		Olympus E-30	Four Thirds	12.2	4032	3024	none	21.3	10.4	530	55
7.		Olympus E-410	Four Thirds	10.0	3648	2736	none	21.1	10.0	494	51
8.		Olympus E-420	Four Thirds	10.0	3648	2736	none	21.5	10.4	527	56
9.		Olympus E-510	Four Thirds	10.0	3648	2736	none	21.2	10.0	442	52
10.		Olympus E-520	Four Thirds	10.0	3648	2736	none	21.4	10.4	548	55
11.		Olympus E-600	Four Thirds	12.2	4032	3024	none	21.5	10.3	541	55
12.		Olympus E-620	Four Thirds	12.2	4032	3024	none	21.3	10.3	536	55
13.		Samsung NX1	APS-C	28.0	6480	4320	4K/30p	24.2	13.2	1363	83
14.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
15.		Sony A7C	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3407	95
16.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
17.		Sony A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
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 A7 indeed provides for movie recording, while the E-3 does not. The highest resolution format that the A7 can use is 1080/60p.

Feature comparison

Beyond 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-3 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 viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the A7 has a higher magnification than the one of the E-3 (0.71x vs 0.58x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The table below summarizes some of the other core capabilities of the Olympus E-3 and Sony A7 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-3	optical	Y	2.5 / 230	swivel	n	1/8000s	5.0/s	Y	Y
2.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
3.		Nikon D300	optical	Y	3.0 / 922	fixed	n	1/8000s	6.0/s	Y	n
4.		Olympus E-1	optical	Y	1.8 / 134	fixed	n	1/4000s	3.0/s	n	n
5.		Olympus E-5	optical	Y	3.0 / 920	swivel	n	1/8000s	5.0/s	Y	Y
6.		Olympus E-30	optical	Y	2.7 / 230	swivel	n	1/8000s	5.0/s	Y	Y
7.		Olympus E-410	optical	n	2.5 / 215	fixed	n	1/4000s	3.0/s	Y	n
8.		Olympus E-420	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	n
9.		Olympus E-510	optical	n	2.5 / 215	fixed	n	1/4000s	3.0/s	Y	Y
10.		Olympus E-520	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	Y
11.		Olympus E-600	optical	n	2.7 / 230	swivel	n	1/4000s	4.0/s	Y	Y
12.		Olympus E-620	optical	n	2.7 / 230	swivel	n	1/4000s	4.0/s	Y	Y
13.		Samsung NX1	2360	Y	3.0 / 1036	tilting	Y	1/8000s	15.0/s	Y	n
14.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
15.		Sony A7C	2360	n	3.0 / 922	swivel	Y	1/4000s	10.0/s	n	Y
16.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
17.		Sony A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	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-3 has one, while the A7 does not. While the built-in flash of the E-3 is not very powerful, it can at times be useful as a fill-in light.

The E-3 writes its imaging data to Compact Flash or xD Picture cards, while the A7 uses SDXC or Memory Stick PRO Duo cards. The E-3 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-3 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-3	Y	- / -	-	-	-	2.0	-	-	-
2.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
3.		Nikon D300	Y	- / -	-	-	mini	2.0	-	-	-
4.		Olympus E-1	Y	- / -	-	-	-	2.0	-	-	-
5.		Olympus E-5	Y	stereo / -	-	-	mini	2.0	-	-	-
6.		Olympus E-30	Y	- / -	-	-	-	2.0	-	-	-
7.		Olympus E-410	Y	- / -	-	-	-	2.0	-	-	-
8.		Olympus E-420	Y	- / -	-	-	-	2.0	-	-	-
9.		Olympus E-510	Y	- / -	-	-	-	2.0	-	-	-
10.		Olympus E-520	Y	- / -	-	-	-	2.0	-	-	-
11.		Olympus E-600	Y	- / -	-	-	-	2.0	-	-	-
12.		Olympus E-620	Y	- / -	-	-	-	2.0	-	-	-
13.		Samsung NX1	Y	stereo / mono	Y	Y	micro	3.0	Y	Y	Y
14.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
15.		Sony A7C	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
16.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
17.		Sony A7S	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-

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-3 does not provide wifi capability.

Studio photographers will appreciate that the Olympus E-3 (unlike the A7) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the E-3 and the A7 have been discontinued, but can regularly be found used on ebay. The E-3 was replaced by the Olympus E-5, while the A7 was followed by the Sony A7 II. Further information on the features and operation of the E-3 and A7 can be found, respectively, in the Olympus E-3 Manual (free pdf) or the online Sony A7 Manual.

Review summary

So what is the bottom line? Which of the two cameras – the Olympus E-3 or the Sony A7 – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.

Reasons to prefer the Olympus E-3:

• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Easier setting verification: Features an LCD display on top to control shooting parameters.
• 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 (750 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.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• More heavily discounted: Has been available for much longer (launched in October 2007).

Advantages of the Sony Alpha A7:

• More detail: Has more megapixels (24 vs 10MP), which boosts linear resolution by 58%.
• Better image quality: Scores substantially higher (34 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 (3.7 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (2 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.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.71x vs 0.58x).
• Larger screen: Has a bigger rear LCD (3.0" vs 2.5") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (1230k vs 230k dots).
• More compact: Is smaller (127x94mm vs 142x116mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 402g or 46 percent) and is thus easier to take along.
• Easier travel charging: Can be conveniently charged via its USB port.
• 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 6 years of technical progress since the E-3 launch.

If the count of individual advantages (bullet points above) is taken as a guide, the A7 is the clear winner of the contest (18 : 10 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 wildlife photographer will view the differences between cameras in a way that diverges from the perspective of a family photog, and a person interested in architecture has distinct needs from a sports 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-3 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains incomplete and does no justice, for example, to the way the E-3 or the A7 perform in practice. 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 expert reviews 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	Street Price
1.		Olympus E-3	..	88/100	..	+ +	o	4/5	Oct 2007	US$ 1 699	ebay.com
2.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	US$ 1 699	ebay.com
3.		Nikon D300	..	+ +	..	+ +	5/5	4.5/5	Aug 2007	US$ 1 799	ebay.com
4.		Olympus E-1	..	..	..	+	o	..	Jun 2003	US$ 1 699	ebay.com
5.		Olympus E-5	4/5	..	..	75/100	4/5	4.5/5	Sep 2010	US$ 1 699	ebay.com
6.		Olympus E-30	..	..	..	71/100	4.5/5	4/5	Nov 2008	US$ 1 299	ebay.com
7.		Olympus E-410	..	86/100	..	+ +	4/5	4.5/5	Mar 2007	US$ 699	ebay.com
8.		Olympus E-420	..	85/100	..	+ +	4/5	4.5/5	Mar 2008	US$ 599	ebay.com
9.		Olympus E-510	..	89/100	..	+ +	3.5/5	4.5/5	Mar 2007	US$ 799	ebay.com
10.		Olympus E-520	..	87/100	..	+ +	4.5/5	4.5/5	May 2008	US$ 699	ebay.com
11.		Olympus E-600	..	..	..	..	..	4.5/5	Aug 2009	US$ 449	ebay.com
12.		Olympus E-620	3/5	88/100	..	72/100	4.5/5	5/5	Feb 2009	US$ 699	ebay.com
13.		Samsung NX1	5/5	..	..	87/100	5/5	5/5	Sep 2014	US$ 1 499	ebay.com
14.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	US$ 1 999	ebay.com
15.		Sony A7C	3.5/5	..	3.5/5	86/100	4/5	4/5	Sep 2020	US$ 1 799	amazon.com
16.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	US$ 2 299	ebay.com
17.		Sony A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	US$ 2 499	ebay.com
Note: (+ +) 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. 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. 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

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