Nikon D5100 vs Olympus E-M1 III
The Nikon D5100 and the Olympus OM-D E-M1 Mark III are two digital cameras that were revealed to the public, respectively, in April 2011 and February 2020. The D5100 is a DSLR, while the E-M1 III is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (D5100) and a Four Thirds (E-M1 III) sensor. The Nikon has a resolution of 16.1 megapixels, whereas the Olympus provides 20.2 MP.
Below is an overview of the main specs of the two cameras as a starting point for the comparison.
Going beyond this snapshot of core features and characteristics, what are the differences between the Nikon D5100 and the Olympus OM-D E-M1 Mark III? 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 physical size and weight of the Nikon D5100 and the Olympus E-M1 III are illustrated 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 Olympus E-M1 III is somewhat smaller (2 percent) than the Nikon D5100. However, the E-M1 III is slightly heavier (4 percent) than the D5100. It is noteworthy in this context that the E-M1 III is splash and dust-proof, while the D5100 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 Nikon Lens Catalog (D5100) and the Micro Four Thirds Lens Catalog (E-M1 III). Mirrorless cameras, such as the E-M1 III, 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 D5100 gets 660 shots out of its EN-EL14 battery, while the E-M1 III can take 420 images on a single charge of its BLH-1 power pack. The power pack in the E-M1 III 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 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.
|1.||Nikon D5100||128 mm||97 mm||79 mm||560 g||660||n||Apr 2011||749|
|2.||Olympus E-M1 III||134 mm||91 mm||69 mm||580 g||420||Y||Feb 2020||1,799|
|3.||Canon G1 X||117 mm||81 mm||65 mm||534 g||250||n||Jan 2012||799|
|4.||Canon 550D||129 mm||98 mm||62 mm||530 g||440||n||Feb 2010||699|
|5.||Nikon D5600||124 mm||97 mm||70 mm||465 g||970||n||Nov 2016||699|
|6.||Nikon D5500||124 mm||97 mm||70 mm||420 g||820||n||Jan 2015||899|
|7.||Nikon D5300||125 mm||98 mm||76 mm||480 g||600||n||Oct 2013||799|
|8.||Nikon D3200||125 mm||96 mm||77 mm||505 g||540||n||Apr 2012||599|
|9.||Nikon D5200||129 mm||98 mm||78 mm||555 g||500||n||Nov 2012||749|
|10.||Nikon D7000||132 mm||105 mm||77 mm||780 g||1050||Y||Sep 2010||1,499|
|11.||Nikon D3100||124 mm||96 mm||75 mm||505 g||550||n||Aug 2010||599|
|12.||Nikon D5000||127 mm||104 mm||80 mm||590 g||510||n||Apr 2009||749|
|13.||Olympus E-M5 III||125 mm||85 mm||50 mm||414 g||310||Y||Oct 2019||1,199|
|14.||Olympus E-M1X||144 mm||147 mm||75 mm||997 g||870||Y||Jan 2019||2,999|
|15.||Olympus E-M1 II||134 mm||91 mm||67 mm||574 g||440||Y||Sep 2016||1,999|
|16.||Panasonic G90||130 mm||94 mm||77 mm||536 g||290||Y||Apr 2019||999|
|17.||Panasonic G9||137 mm||97 mm||92 mm||658 g||400||Y||Nov 2017||1,699|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
Any camera decision will obviously take relative prices into account. The retail prices at the time of the camera’s release place the model in the market relative to other models in the producer’s line-up and the competition. The D5100 was launched at a markedly lower price (by 58 percent) than the E-M1 III, 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 size of the sensor inside a digital camera is one of the key determinants 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. 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 more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Nikon D5100 features an APS-C sensor and the Olympus E-M1 III a Four Thirds sensor. The sensor area in the E-M1 III is 39 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 2.0. The sensor in the D5100 has a native 3:2 aspect ratio, while the one in the E-M1 III offers a 4:3 aspect.
In terms of underlying technology, both cameras are build around CMOS sensors.
Despite having a smaller sensor, the E-M1 III offers a higher resolution of 20.2 megapixels, compared with 16.1 MP of the D5100. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.34μm versus 4.80μm for the D5100). However, it should be noted that the E-M1 III is much more recent (by 8 years and 10 months) than the D5100, and its sensor will have benefitted from technological advances during this time that make it possible to gather light more efficiently. Coming back to sensor resolution, it should be mentioned that the E-M1 III has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Olympus E-M1 III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the E-M1 III for good quality output (200 dots per inch) amounts to 25.9 x 19.4 inches or 65.8 x 49.4 cm, for very good quality (250 dpi) 20.7 x 15.6 inches or 52.7 x 39.5 cm, and for excellent quality (300 dpi) 17.3 x 13 inches or 43.9 x 32.9 cm. The corresponding values for the Nikon D5100 are 24.6 x 16.3 inches or 62.6 x 41.5 cm for good quality, 19.7 x 13.1 inches or 50.1 x 33.2 cm for very good quality, and 16.4 x 10.9 inches or 41.7 x 27.6 cm for excellent quality prints.
The E-M1 III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the D5100, the E-M1 III has the capacity to capture high quality composite images (80MP) by combining multiple shots after shifting its sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).
The Nikon D5100 has a native sensitivity range from ISO 100 to ISO 6400, which can be extended to ISO 100-25600. The corresponding ISO settings for the Olympus OM-D E-M1 Mark III are ISO 200 to ISO 25600, with the possibility to increase the ISO range to 64-25600.
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. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
| DXO |
|2.||Olympus E-M1 III||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|3.||Canon G1 X||1.5-inch||14.2||4352||3264||1080/24p||21.7||10.8||644||60|
|13.||Olympus E-M5 III||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|14.||Olympus E-M1X||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|15.||Olympus E-M1 II||Four Thirds||20.2||5184||3888||4K/30p||23.7||12.8||1312||80|
|16.||Panasonic G90||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|17.||Panasonic G9||Four Thirds||20.2||5184||3888||4K/60p||..||..||..||..|
Many modern cameras are not only capable of taking still images, but can also record movies. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the E-M1 III provides a better video resolution than the D5100. It can shoot movie footage at 4K/30p, while the Nikon is limited to 1080/30p.
Beyond body and sensor, cameras can and do differ across a range of features. For example, the E-M1 III has an electronic viewfinder (2360k dots), while the D5100 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 E-M1 III offers a wider field of view (100%) than the one in the D5100 (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the E-M1 III has a higher magnification (0.74x vs 0.51x), 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 Nikon D5100, the Olympus E-M1 III, and comparable cameras.
|2.||Olympus E-M1 III||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
|3.||Canon G1 X||optical||n||3.0||922||Swivel||n||1/4000s||1.9||Y||Y|
|13.||Olympus E-M5 III||2360||n||3.0||1040||swivel||Y||1/8000s||10.0||n||Y|
|15.||Olympus E-M1 II||2360||n||3.0||1037||swivel||Y||1/8000s||18.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The D5100 has one, while the E-M1 III does not. While the built-in flash of the D5100 is not very powerful, it can at times be useful as a fill-in light.Both cameras have an articulated rear screen that can be turned to be front-facing. This feature will be particularly appreciated by vloggers and photographers who are interested in taking selfies.
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 E-M1 III 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 Nikon D5100 and the Olympus E-M1 III both have an intervalometer built-in. This enables the photographer to capture time lapse sequences, such as flower blooming, a sunset or moon rise, without purchasing an external camera trigger and related software.
Concerning the storage of imaging data, both the D5100 and the E-M1 III write their files to SDXC cards. The E-M1 III features dual card slots, which can be very useful in case a memory card fails. In contrast, the D5100 only has one slot. The E-M1 III supports UHS-II cards (on its first slot), while the D5100 can use UHS-I cards.
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 Nikon D5100 and Olympus OM-D E-M1 Mark III and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|2.||Olympus E-M1 III||Y||stereo||mono||Y||Y||micro||3.1||Y||-||Y|
|3.||Canon G1 X||Y||stereo||mono||-||-||mini||2.0||-||-||-|
|13.||Olympus E-M5 III||Y||stereo||mono||Y||-||micro||2.0||Y||-||Y|
|15.||Olympus E-M1 II||Y||stereo||mono||Y||Y||micro||3.0||Y||-||-|
It is notable that the E-M1 III offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the D5100 does not provide wifi capability.
Studio photographers will appreciate that the Olympus E-M1 III (unlike the D5100) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
The E-M1 III is a recent model that features in the current product line-up of Olympus. In contrast, the D5100 has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the D5100 was succeeded by the Nikon D5200. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Nikon and Olympus websites.
So what conclusions can be drawn? Which of the two cameras – the Nikon D5100 or the Olympus E-M1 III – 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.
Reasons to prefer the Nikon D5100:
- 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 (660 versus 420) on a single battery charge.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (58 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in April 2011).
Arguments in favor of the Olympus OM-D E-M1 Mark III:
- More detail: Has more megapixels (20.2 vs 16.1MP), which boosts linear resolution by 10%.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- High quality composites: Can combine several shots after pixel-shifting its sensor.
- Better video: Provides higher definition movie capture (4K/30p vs 1080/30p).
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- 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 (0.74x vs 0.51x).
- More detailed LCD: Has a higher resolution rear screen (1037k vs 921k dots).
- Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (18 vs 4 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.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- More legacy lens friendly: Can use many non-native lenses via adapters.
- Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- 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.
- Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
- More modern: Reflects 8 years and 10 months of technical progress since the D5100 launch.
If the number of relative strengths (bullet points above) is taken as a guide, the E-M1 III is the clear winner of the contest (25 : 6 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 Nikon D5100 and the Olympus E-M1 III 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 partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the D5100 or the E-M1 III. 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 expert reviews are important. The table below provides a synthesis of the camera assessments of some of the best known photo-gear review sites (amateurphotographer [AP], cameralabs [CL], 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.
|1.||Nikon D5100||5/5||+ +||76/100||4.5/5||4.5/5||Apr 2011||749|
|2.||Olympus E-M1 III||5/5||..||83/100||4.5/5||4/5||Feb 2020||1,799|
|3.||Canon G1 X||5/5||+||76/100||4/5||4.5/5||Jan 2012||799|
|4.||Canon 550D||..||+ +||77/100||4/5||4.5/5||Feb 2010||699|
|5.||Nikon D5600||4/5||..||79/100||4.5/5||4/5||Nov 2016||699|
|6.||Nikon D5500||5/5||+||79/100||4.5/5||4.5/5||Jan 2015||899|
|7.||Nikon D5300||4/5||+ +||79/100||4.5/5||4.5/5||Oct 2013||799|
|8.||Nikon D3200||5/5||+ +||73/100||4.5/5||4.5/5||Apr 2012||599|
|9.||Nikon D5200||4/5||+ +||79/100||4.5/5||4.5/5||Nov 2012||749|
|10.||Nikon D7000||4/5||..||80/100||4.5/5||4.5/5||Sep 2010||1,499|
|11.||Nikon D3100||5/5||+ +||72/100||4.5/5||4.5/5||Aug 2010||599|
|12.||Nikon D5000||..||+ +||75/100||4/5||4.5/5||Apr 2009||749|
|13.||Olympus E-M5 III||5/5||+||82/100||4.5/5||4.5/5||Oct 2019||1,199|
|14.||Olympus E-M1X||4.5/5||o||..||4.5/5||..||Jan 2019||2,999|
|15.||Olympus E-M1 II||5/5||+ +||85/100||4.5/5||4.5/5||Sep 2016||1,999|
|16.||Panasonic G90||4.5/5||+||83/100||4.5/5||4.5/5||Apr 2019||999|
|17.||Panasonic G9||..||+ +||85/100||5/5||5/5||Nov 2017||1,699|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
Care should be taken when interpreting the review scores above, though. The assessments were made in relation to similar cameras of the same technological generation. Hence, a score should always be seen in the context of the camera's market launch date and its price, and comparisons of ratings among very different cameras or across long time periods have little meaning. 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 are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Nikon D5100 vs Olympus E-M1 III
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||Nikon D5100||Olympus E-M1 III|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Nikon F mount lenses||Micro Four Thirds lenses|
|Launch Date||April 2011||February 2020|
|Launch Price||USD 749||USD 1,799|
|Sensor Specs||Nikon D5100||Olympus E-M1 III|
|Sensor Format||APS-C Sensor||Four Thirds Sensor|
|Sensor Size||23.6 x 15.7 mm||17.3 x 13.0 mm|
|Sensor Area||370.52 mm2||224.9 mm2|
|Sensor Diagonal||28.3 mm||21.6 mm|
|Sensor Resolution||16.1 Megapixels||20.2 Megapixels|
|Image Resolution||4928 x 3264 pixels||5184 x 3888 pixels|
|Pixel Pitch||4.80 μm||3.34 μm|
|Pixel Density||4.34 MP/cm2||8.96 MP/cm2|
|Moiré control||Anti-Alias filter||no AA filter|
|Movie Capability||1080/30p Video||4K/30p Video|
|ISO Setting||100 - 6,400 ISO||200 - 25,600 ISO|
|ISO Boost||100 - 25,600 ISO||64 - 25,600 ISO|
|Image Processor||EXPEED 2||TruePic IX|
|DXO Sensor Quality (score)||80||..|
|DXO Color Depth (bits)||23.5||..|
|DXO Dynamic Range (EV)||13.6||..|
|DXO Low Light (ISO)||1183||..|
|Screen Specs||Nikon D5100||Olympus E-M1 III|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||95%||100%|
|Viewfinder Resolution||2360k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||921k dots||1037k dots|
|LCD Attachment||Swivel screen||Swivel screen|
|Touch Input||no Touchscreen||Touchscreen|
|Shooting Specs||Nikon D5100||Olympus E-M1 III|
|Focus System||Phase-detect AF||On-Sensor Phase-detect|
|Manual Focusing Aid||no Peaking Feature||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||4 shutter flaps/s||18 shutter flaps/s|
|Shutter Life Expectancy||100 000 actuations||400 000 actuations|
|Electronic Shutter||no E-Shutter||up to 1/32000s|
|Time-Lapse Photography||Intervalometer built-in||Intervalometer built-in|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Built-in Flash||no On-Board Flash|
|Storage Medium||SDXC cards||SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-I||Single UHS-II|
|Connectivity Specs||Nikon D5100||Olympus E-M1 III|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 3.1|
|HDMI Port||mini HDMI||micro HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||no Wifi||Wifi built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Nikon D5100||Olympus E-M1 III|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||660 shots per charge||420 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
128 x 97 x 79 mm
(5.0 x 3.8 x 3.1 in)
134 x 91 x 69 mm
(5.3 x 3.6 x 2.7 in)
|Camera Weight||560 g (19.8 oz)||580 g (20.5 oz)|
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