Olympus E-420 vs Sony A7S
The Olympus E-420 and the Sony Alpha A7S are two digital cameras that were officially introduced, respectively, in March 2008 and April 2014. The E-420 is a DSLR, while the A7S is a mirrorless interchangeable lens camera. The cameras are based on a Four Thirds (E-420) and a full frame (A7S) sensor. The Olympus has a resolution of 10 megapixels, whereas the Sony provides 12 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
|Olympus E-420||Sony A7S|
|Digital single lens reflex||Mirrorless system camera|
|Four Thirds lenses||Sony E mount lenses|
|10 MP, Four Thirds Sensor||12 MP, Full Frame Sensor|
|no Video||1080/60p Video|
|ISO 100-1,600||ISO 100-102,400 (50 - 409,600)|
|Optical viewfinder||Electronic viewfinder (2400k dots)|
|2.7 LCD, 215k dots||3.0 LCD, 921k dots|
|Fixed screen (not touch-sensitive)||Tilting screen (not touch-sensitive)|
|3.5 shutter flaps per second||5 shutter flaps per second|
|not weather sealed||Weathersealed body|
|500 shots per battery charge||380 shots per battery charge|
|130 x 91 x 53 mm, 440 g||127 x 94 x 48 mm, 489 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus E-420 and the Sony Alpha A7S? 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.
The side-by-side display below illustrates the physical size and weight of the Olympus E-420 and the Sony A7S. 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 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 Olympus E-420 and the Sony A7S are of equal size. However, the A7S is markedly heavier (11 percent) than the E-420. It is noteworthy in this context that the A7S 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 (A7S). Mirrorless cameras, such as the A7S, 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 BLS-1 battery, while the A7S can take 380 images on a single charge of its NP-FW50 power pack. The power pack in the A7S can be charged via the USB port, which can be very convenient when travelling.
The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. If you would like to visualize and compare a different camera combination, just use the right or left arrows in the table to switch to the respective camera. Alternatively, you can also navigate to the CAM-parator app and make your selection from the full list of cameras there.
|Olympus E-420||5.1 in||3.6 in||2.1 in||15.5 oz||500||n||Mar 2008||599|
|Sony A7S||5.0 in||3.7 in||1.9 in||17.2 oz||380||Y||Apr 2014||2,499|
|Nikon Df||5.7 in||4.3 in||2.6 in||26.8 oz||1400||Y||Nov 2013||2,749|
|Nikon D3000||5.0 in||3.8 in||2.5 in||18.9 oz||500||n||Jul 2009||599|
|Nikon D60||5.0 in||3.7 in||2.5 in||18.4 oz||500||n||Jan 2008||629|
|Nikon D40X||4.9 in||3.7 in||2.5 in||18.4 oz||520||n||Mar 2007||729|
|Olympus E-450||5.1 in||3.6 in||2.1 in||15.5 oz||500||n||Mar 2009||499|
|Olympus E-600||5.1 in||3.7 in||2.4 in||18.9 oz||500||n||Aug 2009||449|
|Olympus E-620||5.1 in||3.7 in||2.4 in||18.4 oz||500||n||Feb 2009||699|
|Olympus E-520||5.4 in||3.6 in||2.7 in||18.9 oz||750||n||May 2008||699|
|Olympus E-410||5.1 in||3.6 in||2.1 in||15.3 oz||500||n||Mar 2007||699|
|Olympus E-400||5.1 in||3.6 in||2.1 in||15.3 oz||500||n||Sep 2006||699|
|Panasonic L10||5.3 in||3.8 in||3.1 in||19.6 oz||450||n||Aug 2007||599|
|Sony A7S II||5.0 in||3.8 in||2.4 in||22.1 oz||370||Y||Sep 2015||2,999|
|Sony A7 II||5.0 in||3.8 in||2.4 in||21.1 oz||350||Y||Nov 2014||1,999|
|Sony A7||5.0 in||3.7 in||1.9 in||16.7 oz||340||Y||Oct 2013||1,699|
|Sony A7R||5.0 in||3.7 in||1.9 in||16.4 oz||340||Y||Oct 2013||2,299|
Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
(1) Number of images that can be taken on a full battery charge according to the CIPA-standard; (2) Official announcement.
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-420 was launched at a markedly lower price (by 76 percent) than the A7S, 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.
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 tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units 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 tend to be more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Olympus E-420 features a Four Thirds sensor and the Sony A7S a full frame sensor. The sensor area in the A7S 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-420 has a native 4:3 aspect ratio, while the one in the A7S offers a 3:2 aspect.
In terms of underlying technology, both cameras are build around CMOS sensors.
With 12MP, the A7S offers a higher resolution than the E-420 (10MP), but the A7S nevertheless has larger individual pixels (pixel pitch of 8.45μm versus 4.74μm for the E-420) due to its larger sensor. Moreover, the A7S is a much more recent model (by 6 years and 1 month) 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.
The resolution advantage of the Sony A7S implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7S for good quality output (200 dots per inch) amounts to 21.2 x 14.2 inches or 53.8 x 36 cm, for very good quality (250 dpi) 17 x 11.3 inches or 43.1 x 28.8 cm, and for excellent quality (300 dpi) 14.1 x 9.4 inches or 35.9 x 24 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 A7S are ISO 100 to ISO 102400, with the possibility to increase the ISO range to 50-409600.
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 A7S offers substantially better image quality than the E-420 (overall score 31 points higher). The advantage is based on 2.4 bits higher color depth, 2.8 EV in additional dynamic range, and 2.8 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.
|Olympus E-420||Four Thirds||10.0||3648||2736||none||21.5||10.4||527||56|
|Sony A7S||Full Frame||12.0||4240||2832||1080/60p||23.9||13.2||3702||87|
|Nikon Df||Full Frame||16.2||4928||3280||none||24.6||13.1||3279||89|
|Olympus E-450||Four Thirds||10.0||3648||2736||none||21.5||10.5||512||56|
|Olympus E-600||Four Thirds||12.2||4032||3024||none||21.5||10.3||541||55|
|Olympus E-620||Four Thirds||12.2||4032||3024||none||21.3||10.3||536||55|
|Olympus E-520||Four Thirds||10.0||3648||2736||none||21.4||10.4||548||55|
|Olympus E-410||Four Thirds||10.0||3648||2736||none||21.1||10.0||494||51|
|Olympus E-400||Four Thirds||10.0||3648||2736||none||..||..||..||..|
|Panasonic L10||Four Thirds||10.0||3648||2736||none||21.3||10.8||429||55|
|Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|Sony A7||Full Frame||24.0||6000||4000||1080/60p||24.8||14.2||2248||90|
|Sony A7R||Full Frame||36.2||7360||4912||1080/60p||25.6||14.1||2746||95|
Many modern cameras cannot only take still pictures, but also record videos. The A7S indeed provides for movie recording, while the E-420 does not. The highest resolution format that the A7S can use is 1080/60p.
Apart from body and sensor, cameras can and do differ across a range of features. For example, the A7S 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 A7S 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 A7S 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 adjacent table lists some of the other core features of the Olympus E-420 and Sony A7S along with similar information for a selection of comparators.
|Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The E-420 has one, while the A7S 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 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, the A7S is one of those camera that have an additional 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 E-420 writes its imaging data to Compact Flash or xD Picture cards, while the A7S 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 A7S only has one slot.
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 A7S and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
|Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the A7S 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 A7S have been discontinued, but can regularly be found used on eBay. The A7S was replaced by the Sony A7S II, while the E-420 does not have a direct successor. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Olympus and Sony websites.
So how do things add up? Is there a clear favorite between the Olympus E-420 and the Sony A7S? 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:
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- Less heavy: Is lighter (by 49g or 10 percent) and hence easier to carry around.
- Longer lasting: Can take more shots (500 versus 380) 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 (76 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in March 2008).
Arguments in favor of the Sony Alpha A7S:
- More detail: Has more megapixels (12 vs 10MP), which boosts linear resolution by 12%.
- Better image quality: Scores substantially higher (31 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (2.4 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (2.8 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (2.8 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 (921k 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 (5 vs 3.5 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- 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 6 years and 1 month of technical progress since the E-420 launch.
If the count of relative strengths (bullet points above) is taken as a measure, the A7S is the clear winner of the contest (20 : 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 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 A7S 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 remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the E-420 or the A7S. 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.
This is why hands-on reviews by experts are important. The table below provides a synthesis of the camera assessments of some of the best known photo-gear review sites (cameralabs, dpreview, ephotozine, imaging-resource, and photographyblog). 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.
|Olympus E-420||85/100||+ +||4/5||o||4.5/5||Mar 2008||599|
|Sony A7S||..||86/100||4.5/5||4.5/5||5/5||Apr 2014||2,499|
|Nikon Df||..||81/100||4/5||4/5||4/5||Nov 2013||2,749|
|Nikon D3000||+||72/100||4/5||3.5/5||4.5/5||Jul 2009||599|
|Nikon D60||80/100||+ +||4/5||o||4.5/5||Jan 2008||629|
|Nikon D40X||79/100||+ +||4/5||o||4/5||Mar 2007||729|
|Olympus E-450||..||..||4/5||..||4/5||Mar 2009||499|
|Olympus E-600||..||..||..||..||4.5/5||Aug 2009||449|
|Olympus E-620||88/100||72/100||4.5/5||o||5/5||Feb 2009||699|
|Olympus E-520||87/100||+ +||4.5/5||4/5||4.5/5||May 2008||699|
|Olympus E-410||86/100||+ +||4/5||o||4.5/5||Mar 2007||699|
|Olympus E-400||85/100||..||4/5||..||4/5||Sep 2006||699|
|Panasonic L10||85/100||+||3.5/5||o||4/5||Aug 2007||599|
|Sony A7S II||+||..||4.5/5||5/5||5/5||Sep 2015||2,999|
|Sony A7 II||+||82/100||4.5/5||5/5||5/5||Nov 2014||1,999|
|Sony A7||+ +||80/100||5/5||4.5/5||5/5||Oct 2013||1,699|
|Sony A7R||+ +||82/100||4.5/5||5/5||5/5||Oct 2013||2,299|
|Notes: (+ +) 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. 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.
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 make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
- Canon 1200D vs Olympus E-420
- Canon 1D Mark II vs Sony A7S
- Canon 6D vs Olympus E-420
- Canon G7 X Mark III vs Sony A7S
- Leica M Typ 240 vs Olympus E-420
- Leica V-LUX 3 vs Sony A7S II
- Nikon D610 vs Sony A7S
- Olympus E-30 vs Sony A7S II
- Olympus E-420 vs Olympus E-P3
- Panasonic GH5s vs Sony A7S II
- Panasonic GX7 vs Sony A7S II
- Pentax MX-1 vs Sony A7S II
Specifications: Olympus E-420 vs Sony A7S
Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.
|Camera Model||Olympus E-420||Sony A7S|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Four Thirds lenses||Sony E mount lenses|
|Launch Date||March 2008||April 2014|
|Launch Price||USD 599||USD 2,499|
|Sensor Specs||Olympus E-420||Sony A7S|
|Sensor Format||Four Thirds Sensor||Full Frame Sensor|
|Sensor Size||17.3 x 13.0 mm||35.8 x 23.9 mm|
|Sensor Area||224.9 mm2||855.62 mm2|
|Sensor Diagonal||21.6 mm||43 mm|
|Sensor Resolution||10 Megapixels||12 Megapixels|
|Image Resolution||3648 x 2736 pixels||4240 x 2832 pixels|
|Pixel Pitch||4.74 μm||8.45 μm|
|Pixel Density||4.44 MP/cm2||1.40 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||no Video||1080/60p Video|
|ISO Setting||100 - 1,600 ISO||100 - 102,400 ISO|
|ISO Boost||no Enhancement||50 - 409,600 ISO|
|Image Processor||TruePic III||BIONZ X|
|DXO Sensor Quality (score)||56||87|
|DXO Color Depth (bits)||21.5||23.9|
|DXO Dynamic Range (EV)||10.4||13.2|
|DXO Low Light (ISO)||527||3702|
|Screen Specs||Olympus E-420||Sony A7S|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||95%||100%|
|Viewfinder Resolution||2400k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||2.7inch||3.0inch|
|LCD Resolution||215k dots||921k dots|
|LCD Attachment||Fixed screen||Tilting screen|
|Shooting Specs||Olympus E-420||Sony A7S|
|Focus System||Phase-detect AF||Contrast-detect AF|
|Manual Focusing Aid||no Peaking Feature||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||3.5 shutter flaps/s||5 shutter flaps/s|
|Electronic Shutter||no E-Shutter||YES|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||CF or XD cards||MS or SDXC cards|
|Second Storage Option||Dual card slots||Single card slot|
|Connectivity Specs||Olympus E-420||Sony A7S|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||no HDMI||micro HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||no Wifi||Wifi built-in|
|Near-Field Communication||no NFC||NFC built-in|
|Body Specs||Olympus E-420||Sony A7S|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||500 shots per charge||380 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
130 x 91 x 53 mm
(5.1 x 3.6 x 2.1 in)
127 x 94 x 48 mm
(5.0 x 3.7 x 1.9 in)
|Camera Weight||440 g (15.5 oz)||489 g (17.2 oz)|
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