Olympus E-420 vs Sony A7R

The Olympus E-420 and the Sony Alpha A7R are two digital cameras that were officially introduced, respectively, in March 2008 and October 2013. The E-420 is a DSLR, while the A7R is a mirrorless interchangeable lens camera. The cameras are based on a Four Thirds (E-420) and a full frame (A7R) sensor. The Olympus has a resolution of 10 megapixels, whereas the Sony provides 36.2 MP.

Below is an overview of the main specs of the two cameras as a starting point for the comparison.

Headline Specifications

Olympus E-420		Sony A7R
Digital single lens reflex		Mirrorless system camera
Four Thirds lenses		Sony E mount lenses
10 MP – Four Thirds sensor		36.2 MP – Full Frame sensor
no Video		1080/60p Video
ISO 100-1,600		ISO 100-25,600 (50 - 51,200)
Optical viewfinder		Electronic viewfinder (2400k dots)
2.7" LCD – 215k dots		3.0" LCD – 1230k dots
Fixed screen (not touch-sensitive)		Tilting screen (no touchscreen)
3.5 shutter flaps per second		4 shutter flaps per second
not weather sealed		Weathersealed body
500 shots per battery charge		340 shots per battery charge
130 x 91 x 53 mm, 440 g		127 x 94 x 48 mm, 465 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus E-420 and the Sony Alpha A7R? 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-420 and the Sony A7R 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 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 Olympus E-420 and the Sony A7R are of equal size. However, the A7R is markedly heavier (6 percent) than the E-420. It is noteworthy in this context that the A7R is splash and dust-proof, while the E-420 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-420) and the Sony FE Lens Catalog (A7R). Mirrorless cameras, such as the A7R, 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-420 gets 500 shots out of its Olympus BLS-1 battery, while the A7R can take 340 images on a single charge of its Sony NP-FW50 power pack. The power pack in the A7R 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 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.

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-420	130 mm	91 mm	53 mm	440 g	500	n	Mar 2008	US$ 599	ebay.com
2.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	US$ 2 299	ebay.com
3.		Nikon D40X	124 mm	94 mm	64 mm	522 g	520	n	Mar 2007	US$ 729	ebay.com
4.		Nikon D60	126 mm	94 mm	64 mm	522 g	500	n	Jan 2008	US$ 629	ebay.com
5.		Nikon D3000	126 mm	97 mm	64 mm	536 g	500	n	Jul 2009	US$ 599	ebay.com
6.		Olympus E-400	130 mm	91 mm	53 mm	435 g	500	n	Sep 2006	US$ 699	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-450	130 mm	91 mm	53 mm	440 g	500	n	Mar 2009	US$ 499	ebay.com
9.		Olympus E-520	136 mm	92 mm	68 mm	535 g	750	n	May 2008	US$ 699	ebay.com
10.		Olympus E-600	130 mm	94 mm	60 mm	535 g	500	n	Aug 2009	US$ 449	ebay.com
11.		Olympus E-620	130 mm	94 mm	60 mm	521 g	500	n	Feb 2009	US$ 699	ebay.com
12.		Panasonic L10	135 mm	96 mm	78 mm	556 g	450	n	Aug 2007	US$ 599	ebay.com
13.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	US$ 1 699	ebay.com
14.		Sony A7 IV	131 mm	96 mm	80 mm	659 g	580	Y	Oct 2021	US$ 2 499	amazon.com
15.		Sony A7C II	124 mm	71 mm	63 mm	514 g	540	Y	Aug 2023	US$ 2 199	amazon.com
16.		Sony A7R II	127 mm	96 mm	60 mm	625 g	290	Y	Jun 2015	US$ 3 199	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 naturally be influenced heavily by the price. 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-420 was launched at a markedly lower price (by 74 percent) than the A7R, 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. 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 associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Olympus E-420 features a Four Thirds sensor and the Sony A7R a full frame sensor. The sensor area in the A7R 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-420 has a native 4:3 aspect ratio, while the one in the A7R offers a 3:2 aspect.

With 36.2MP, the A7R offers a higher resolution than the E-420 (10MP), but the A7R nevertheless has larger individual pixels (pixel pitch of 4.88μm versus 4.74μm for the E-420) due to its larger sensor. Moreover, the A7R is a much more recent model (by 5 years and 7 months) than the E-420, and its sensor will 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 the A7R has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Sony A7R implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7R for good quality output (200 dots per inch) amounts to 36.8 x 24.6 inches or 93.5 x 62.4 cm, for very good quality (250 dpi) 29.4 x 19.6 inches or 74.8 x 49.9 cm, and for excellent quality (300 dpi) 24.5 x 16.4 inches or 62.3 x 41.6 cm. The corresponding values for the Olympus E-420 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 Olympus E-420 has a native sensitivity range from ISO 100 to ISO 1600. The corresponding ISO settings for the Sony Alpha A7R 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 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 A7R offers substantially better image quality than the E-420 (overall score 39 points higher). The advantage is based on 4.1 bits higher color depth, 3.7 EV in additional dynamic range, and 2.4 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-420	Four Thirds	10.0	3648	2736	none	21.5	10.4	527	56
2.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
3.		Nikon D40X	APS-C	10.0	3872	2592	none	22.4	11.4	516	63
4.		Nikon D60	APS-C	10.0	3872	2592	none	22.5	11.4	562	65
5.		Nikon D3000	APS-C	10.0	3872	2592	none	22.3	11.1	563	62
6.		Olympus E-400	Four Thirds	10.0	3648	2736	none	21.0	10.6	127	53
7.		Olympus E-410	Four Thirds	10.0	3648	2736	none	21.1	10.0	494	51
8.		Olympus E-450	Four Thirds	10.0	3648	2736	none	21.5	10.5	512	56
9.		Olympus E-520	Four Thirds	10.0	3648	2736	none	21.4	10.4	548	55
10.		Olympus E-600	Four Thirds	12.2	4032	3024	none	21.5	10.3	541	55
11.		Olympus E-620	Four Thirds	12.2	4032	3024	none	21.3	10.3	536	55
12.		Panasonic L10	Four Thirds	10.0	3648	2736	none	21.3	10.8	429	55
13.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
14.		Sony A7 IV	Full Frame	32.7	7008	4672	4K/60p	25.4	14.7	3379	97
15.		Sony A7C II	Full Frame	32.7	7008	4672	4K/60p	25.4	14.7	3237	96
16.		Sony A7R II	Full Frame	42.2	7952	5304	4K/30p	26.0	13.9	3434	98
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 also of capturing video footage. The A7R indeed provides for movie recording, while the E-420 does not. The highest resolution format that the A7R can use is 1080/60p.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the A7R has an electronic viewfinder (2400k dots), while the E-420 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 A7R offers a wider field of view (100%) than the one in the E-420 (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the A7R has a higher magnification (0.71x vs 0.46x), 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-420 and Sony A7R 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-420	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	n
2.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
3.		Nikon D40X	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
4.		Nikon D60	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
5.		Nikon D3000	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
6.		Olympus E-400	optical	n	2.5 / 215	fixed	n	1/4000s	3.0/s	Y	n
7.		Olympus E-410	optical	n	2.5 / 215	fixed	n	1/4000s	3.0/s	Y	n
8.		Olympus E-450	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	n
9.		Olympus E-520	optical	n	2.7 / 215	fixed	n	1/4000s	3.5/s	Y	Y
10.		Olympus E-600	optical	n	2.7 / 230	swivel	n	1/4000s	4.0/s	Y	Y
11.		Olympus E-620	optical	n	2.7 / 230	swivel	n	1/4000s	4.0/s	Y	Y
12.		Panasonic L10	optical	n	2.5 / 207	swivel	n	1/4000s	3.0/s	Y	n
13.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
14.		Sony A7 IV	3686	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
15.		Sony A7C II	2360	n	3.0 / 1037	swivel	Y	1/4000s	10.0/s	n	Y
16.		Sony A7R II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
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-420 has one, while the A7R does not. While the built-in flash of the E-420 is not very powerful, it can at times be useful as a fill-in light.

The E-420 writes its imaging data to Compact Flash or xD Picture cards, while the A7R uses SDXC or Memory Stick PRO Duo cards. The E-420 features dual card slots, which can be very useful in case a memory card fails. In contrast, the A7R 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-420 and Sony Alpha A7R 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-420	Y	- / -	-	-	-	2.0	-	-	-
2.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
3.		Nikon D40X	Y	- / -	-	-	-	2.0	-	-	-
4.		Nikon D60	Y	- / -	-	-	-	2.0	-	-	-
5.		Nikon D3000	Y	- / -	-	-	-	2.0	-	-	-
6.		Olympus E-400	Y	- / -	-	-	-	2.0	-	-	-
7.		Olympus E-410	Y	- / -	-	-	-	2.0	-	-	-
8.		Olympus E-450	Y	- / -	-	-	-	2.0	-	-	-
9.		Olympus E-520	Y	- / -	-	-	-	2.0	-	-	-
10.		Olympus E-600	Y	- / -	-	-	-	2.0	-	-	-
11.		Olympus E-620	Y	- / -	-	-	-	2.0	-	-	-
12.		Panasonic L10	Y	- / -	-	-	-	2.0	-	-	-
13.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
14.		Sony A7 IV	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
15.		Sony A7C II	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
16.		Sony A7R II	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 A7R offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the E-420 does not provide wifi capability.

Both the E-420 and the A7R have been discontinued, but can regularly be found used on ebay. The A7R was replaced by the Sony A7R II, while the E-420 does not have a direct successor. Further information on the features and operation of the E-420 and A7R can be found, respectively, in the Olympus E-420 Manual (free pdf) or the online Sony A7R Manual.

Review summary

So how do things add up? Is there a clear favorite between the Olympus E-420 and the Sony A7R? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.

Advantages of the Olympus E-420:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Longer lasting: Can take more shots (500 versus 340) on a single battery charge.
• 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 (74 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in March 2008).

Reasons to prefer the Sony Alpha A7R:

• More detail: Has more megapixels (36.2 vs 10MP), which boosts linear resolution by 94%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better image quality: Scores substantially higher (39 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (4.1 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 (2.4 stops ISO advantage).
• Broader imaging potential: Can capture not only stills but also 1080/60p video.
• 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 0.46x).
• 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 215k dots).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (4 vs 3.5 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 5 years and 7 months of technical progress since the E-420 launch.

If the count of relative strengths (bullet points above) is taken as a measure, the A7R is the clear winner of the contest (21 : 7 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 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-420 and the Sony A7R 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 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-420 and the A7R 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 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	Street Price
1.		Olympus E-420	..	85/100	..	+ +	4/5	4.5/5	Mar 2008	US$ 599	ebay.com
2.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	US$ 2 299	ebay.com
3.		Nikon D40X	..	79/100	..	+ +	4/5	4/5	Mar 2007	US$ 729	ebay.com
4.		Nikon D60	..	80/100	..	+ +	4/5	4.5/5	Jan 2008	US$ 629	ebay.com
5.		Nikon D3000	..	+	..	72/100	4/5	4.5/5	Jul 2009	US$ 599	ebay.com
6.		Olympus E-400	..	85/100	..	..	4/5	4/5	Sep 2006	US$ 699	ebay.com
7.		Olympus E-410	..	86/100	..	+ +	4/5	4.5/5	Mar 2007	US$ 699	ebay.com
8.		Olympus E-450	..	..	..	..	4/5	4/5	Mar 2009	US$ 499	ebay.com
9.		Olympus E-520	..	87/100	..	+ +	4.5/5	4.5/5	May 2008	US$ 699	ebay.com
10.		Olympus E-600	..	..	..	..	..	4.5/5	Aug 2009	US$ 449	ebay.com
11.		Olympus E-620	3/5	88/100	..	72/100	4.5/5	5/5	Feb 2009	US$ 699	ebay.com
12.		Panasonic L10	..	85/100	..	+	3.5/5	4/5	Aug 2007	US$ 599	ebay.com
13.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	US$ 1 699	ebay.com
14.		Sony A7 IV	5/5	+ +	4.5/5	89/100	4.5/5	4.5/5	Oct 2021	US$ 2 499	amazon.com
15.		Sony A7C II	4/5	..	4/5	87/100	4.5/5	4.5/5	Aug 2023	US$ 2 199	amazon.com
16.		Sony A7R II	5/5	+ +	5/5	90/100	5/5	5/5	Jun 2015	US$ 3 199	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. A score, therefore, has to be seen in close connection to the price and market introduction time 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. Also, please note that some of the review sites have changed their methodology and reporting over time.

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