Nikon D5100 vs Sony A850
The Nikon D5100 and the Sony Alpha A850 are two digital cameras that were officially introduced, respectively, in April 2011 and August 2009. Both are DSLR (Digital Single Lens Reflex) cameras that are based on an APS-C (D5100) and a full frame (A850) sensor. The Nikon has a resolution of 16.1 megapixels, whereas the Sony provides 24.4 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 Sony Alpha A850? 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.
An illustration of the physical size and weight of the Nikon D5100 and the Sony A850 is provided in the side-by-side display below. 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 size 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 A850 is considerably larger (47 percent) than the Nikon D5100. Moreover, the A850 is substantially heavier (60 percent) than the D5100. It is noteworthy in this context that the A850 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. Hence, you might want to study and compare the specifications of available lenses in order to get the full picture of the size and weight of the two camera systems.
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.
|1.||Nikon D5100||128 mm||97 mm||79 mm||560 g||660||n||Apr 2011||749|
|2.||Sony A850||156 mm||117 mm||82 mm||895 g||880||Y||Aug 2009||1,999|
|3.||Canon T2i||129 mm||98 mm||62 mm||530 g||440||n||Feb 2010||699|
|4.||Nikon D5600||124 mm||97 mm||70 mm||465 g||970||n||Nov 2016||699|
|5.||Nikon D750||141 mm||113 mm||78 mm||750 g||1230||Y||Sep 2014||2,299|
|6.||Nikon D5300||125 mm||98 mm||76 mm||480 g||600||n||Oct 2013||799|
|7.||Nikon D3200||125 mm||96 mm||77 mm||505 g||540||n||Apr 2012||599|
|8.||Nikon D5200||129 mm||98 mm||78 mm||555 g||500||n||Nov 2012||749|
|9.||Nikon D7000||132 mm||105 mm||77 mm||780 g||1050||Y||Sep 2010||1,499|
|10.||Nikon D3100||124 mm||96 mm||75 mm||505 g||550||n||Aug 2010||599|
|11.||Nikon D5000||127 mm||104 mm||80 mm||590 g||510||n||Apr 2009||749|
|12.||Sony A7C||124 mm||71 mm||60 mm||509 g||740||Y||Sep 2020||1,799|
|13.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|14.||Sony A99||147 mm||111 mm||78 mm||812 g||500||Y||Sep 2012||2,799|
|15.||Sony NEX-5R||111 mm||59 mm||39 mm||276 g||330||n||Aug 2012||749|
|16.||Sony NEX-5N||111 mm||59 mm||38 mm||269 g||460||n||Aug 2011||699|
|17.||Sony A900||156 mm||117 mm||82 mm||895 g||880||Y||Sep 2008||2,999|
|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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The D5100 was launched at a markedly lower price (by 63 percent) than the A850, 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.
The size of the imaging sensor is a crucial determinant 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 Nikon D5100 features an APS-C sensor and the Sony A850 a full frame sensor. The sensor area in the A850 is 132 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
Technology-wise, both cameras are equipped with CMOS (Complementary Metal–Oxide–Semiconductor) sensors.
With 24.4MP, the A850 offers a higher resolution than the D5100 (16.1MP), but the A850 nevertheless has larger individual pixels (pixel pitch of 5.94μm versus 4.80μm for the D5100) due to its larger sensor. However, the D5100 is a somewhat more recent model (by 1 year and 7 months) than the A850, and its sensor might have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units.
The resolution advantage of the Sony A850 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A850 for good quality output (200 dots per inch) amounts to 30.2 x 20.2 inches or 76.8 x 51.2 cm, for very good quality (250 dpi) 24.2 x 16.1 inches or 61.4 x 41 cm, and for excellent quality (300 dpi) 20.2 x 13.4 inches or 51.2 x 34.1 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 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 Sony Alpha A850 are ISO 200 to ISO 3200, with the possibility to increase the ISO range to 100-6400.
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"). The Overall DXO ratings for the two cameras under consideration are close, suggesting that they provide similar imaging performance. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
|2.||Sony A850||Full Frame||24.4||6048||4032||none||23.8||12.2||1415||79|
|5.||Nikon D750||Full Frame||24.2||6016||4016||1080/60p||24.8||14.5||2956||93|
|12.||Sony A7C||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3407||95|
|13.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|14.||Sony A99||Full Frame||24.0||6000||4000||1080/60p||25.0||14.0||1555||89|
|17.||Sony A900||Full Frame||24.4||6048||4032||none||23.7||12.3||1431||79|
Many modern cameras cannot only take still pictures, but also record videos. The D5100 indeed provides movie recording capabilities, while the A850 does not. The highest resolution format that the D5100 can use is 1080/30p.
Apart from body and sensor, cameras can and do differ across a range of features. The D5100 and the A850 are similar in the sense that both have an optical viewfinder. The latter is useful for getting a clear image for framing even in brightly lit environments. The viewfinder in the A850 offers a wider field of view (98%) 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 A850 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 table below summarizes some of the other core capabilities of the Nikon D5100 and Sony A850 in connection with corresponding information for a sample of similar cameras.
|1.||Nikon D5100||optical||n||3.0 / 921||swivel||n||1/4000s||4.0||Y||n|
|2.||Sony A850||optical||Y||3.0 / 922||fixed||n||1/8000s||3.0||n||Y|
|3.||Canon T2i||optical||n||3.0 / 1040||fixed||n||1/4000s||3.7||Y||n|
|4.||Nikon D5600||optical||n||3.2 / 1037||swivel||Y||1/4000s||5.0||Y||n|
|5.||Nikon D750||optical||Y||3.2 / 1229||tilting||n||1/4000s||6.0||Y||n|
|6.||Nikon D5300||optical||n||3.2 / 1037||swivel||n||1/4000s||5.0||Y||n|
|7.||Nikon D3200||optical||n||3.0 / 921||fixed||n||1/4000s||4.0||Y||n|
|8.||Nikon D5200||optical||n||3.0 / 921||swivel||n||1/4000s||5.0||Y||n|
|9.||Nikon D7000||optical||Y||3.0 / 921||fixed||n||1/8000s||6.0||Y||n|
|10.||Nikon D3100||optical||n||3.0 / 230||fixed||n||1/4000s||3.0||Y||n|
|11.||Nikon D5000||optical||n||2.7 / 230||full-flex||n||1/4000s||4.0||Y||n|
|12.||Sony A7C||2360||n||3.0 / 922||swivel||Y||1/4000s||10.0||n||Y|
|13.||Sony A7 III||2359||n||3.0 / 922||tilting||Y||1/8000s||10.0||n||Y|
|14.||Sony A99||2359||Y||3.0 / 1229||full-flex||n||1/8000s||6.0||n||Y|
|15.||Sony NEX-5R||optional||n||3.0 / 920||tilting||Y||1/4000s||10.0||n||n|
|16.||Sony NEX-5N||optional||n||3.0 / 920||tilting||Y||1/4000s||10.0||n||n|
|17.||Sony A900||optical||Y||3.0 / 922||fixed||n||1/8000s||5.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The D5100 has one, while the A850 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.The D5100 has an articulated LCD that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in snapping selfies. In contrast, the A850 does not have a selfie-screen.
The Nikon D5100 has 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.
The D5100 writes its imaging data to SDXC cards, while the A850 uses Compact Flash or Memory Stick PRO Duo cards. The A850 features dual card slots, which can be very useful in case a memory card fails. In contrast, the D5100 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 Nikon D5100 and Sony Alpha A850 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
Mic / Speaker
|1.||Nikon D5100||Y||mono / mono||Y||-||mini||2.0||-||-||-|
|2.||Sony A850||Y||- / -||-||-||mini||2.0||-||-||-|
|3.||Canon T2i||Y||stereo / -||Y||-||mini||2.0||-||-||-|
|4.||Nikon D5600||Y||stereo / mono||Y||-||mini||2.0||Y||Y||Y|
|5.||Nikon D750||Y||stereo / mono||Y||Y||mini||2.0||Y||-||-|
|6.||Nikon D5300||Y||stereo / mono||Y||-||mini||2.0||Y||-||-|
|7.||Nikon D3200||Y||mono / mono||Y||-||mini||2.0||-||-||-|
|8.||Nikon D5200||Y||stereo / mono||Y||-||mini||2.0||-||-||-|
|9.||Nikon D7000||Y||mono / mono||Y||-||mini||2.0||-||-||-|
|10.||Nikon D3100||Y||mono / mono||-||-||mini||2.0||-||-||-|
|11.||Nikon D5000||Y||mono / mono||-||-||mini||2.0||-||-||-|
|12.||Sony A7C||Y||stereo / mono||Y||Y||micro||3.2||Y||Y||Y|
|13.||Sony A7 III||Y||stereo / mono||Y||Y||micro||3.1||Y||Y||Y|
|14.||Sony A99||Y||stereo / mono||Y||Y||mini||2.0||-||-||-|
|15.||Sony NEX-5R||Y||stereo / mono||-||-||mini||2.0||Y||-||-|
|16.||Sony NEX-5N||Y||stereo / mono||-||-||mini||2.0||-||-||-|
|17.||Sony A900||Y||- / -||-||-||mini||2.0||-||-||-|
Studio photographers will appreciate that the Sony A850 (unlike the D5100) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the D5100 and the A850 have been discontinued, but can regularly be found used on eBay. The D5100 was replaced by the Nikon D5200, while the A850 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 Nikon and Sony websites.
So what is the bottom line? Is there a clear favorite between the Nikon D5100 and the Sony A850? Which camera is better? The listing below highlights the relative strengths of the two models.
Advantages of the Nikon D5100:
- More dynamic range: Captures a larger spectrum of light and dark details (1.4 EV of extra DR).
- Broader imaging potential: Can record not only still images but also 1080/30p movies.
- 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.
- Faster burst: Shoots at higher frequency (4 vs 3 flaps/sec) to capture the decisive moment.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More compact: Is smaller (128x97mm vs 156x117mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 335g or 37 percent) and hence easier to carry around.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (63 percent cheaper at launch).
- More modern: Is somewhat more recent (announced 1 year and 7 months after the A850).
Reasons to prefer the Sony Alpha A850:
- More detail: Has more megapixels (24.4 vs 16.1MP), which boosts linear resolution by 23%.
- More complete view: Has a viewfinder with a larger field of view (98% vs 95%).
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.74x vs 0.51x).
- Easier setting verification: Features a control panel on top to check shooting parameters.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Longer lasting: Gets more shots (880 versus 660) out of a single battery charge.
- 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.
- 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 on the market for longer (launched in August 2009).
If the count of individual advantages (bullet points above) is taken as a guide, the match-up finishes in a tie (11 points each). 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 Nikon D5100 and the Sony A850 place the cameras among the top in their class? Find out in the latest Best DSLR Camera listing 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 remains incomplete and does no justice, for example, to the way the D5100 or the A850 perform in practice. 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.
This is where reviews by experts come in. 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.
|1.||Nikon D5100||5/5||+ +||..||76/100||4.5/5||4.5/5||Apr 2011||749|
|2.||Sony A850||3/5||..||..||75/100||..||4.5/5||Aug 2009||1,999|
|3.||Canon T2i||..||+ +||..||77/100||4/5||4.5/5||Feb 2010||699|
|4.||Nikon D5600||4/5||..||4/5||79/100||4.5/5||4/5||Nov 2016||699|
|5.||Nikon D750||5/5||+ +||4/5||90/100||4.5/5||4.5/5||Sep 2014||2,299|
|6.||Nikon D5300||4/5||+ +||..||79/100||4.5/5||4.5/5||Oct 2013||799|
|7.||Nikon D3200||5/5||+ +||..||73/100||4.5/5||4.5/5||Apr 2012||599|
|8.||Nikon D5200||4/5||+ +||..||79/100||4.5/5||4.5/5||Nov 2012||749|
|9.||Nikon D7000||4/5||..||..||80/100||4.5/5||4.5/5||Sep 2010||1,499|
|10.||Nikon D3100||5/5||+ +||..||72/100||4.5/5||4.5/5||Aug 2010||599|
|11.||Nikon D5000||..||+ +||..||75/100||4/5||4.5/5||Apr 2009||749|
|12.||Sony A7C||3.5/5||..||3.5/5||86/100||4/5||4/5||Sep 2020||1,799|
|13.||Sony A7 III||..||+ +||4.5/5||89/100||5/5||5/5||Feb 2018||1,999|
|14.||Sony A99||5/5||..||..||84/100||4.5/5||4.5/5||Sep 2012||2,799|
|15.||Sony NEX-5R||..||..||..||..||4.5/5||4.5/5||Aug 2012||749|
|16.||Sony NEX-5N||3/5||+ +||..||79/100||4.5/5||4.5/5||Aug 2011||699|
|17.||Sony A900||..||+ +||..||+ +||4.5/5||5/5||Sep 2008||2,999|
|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. Also, please note that some of the review sites have changed their methodology and reporting over time.
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.
- Canon 77D vs Sony A850
- Canon SX410 vs Sony A850
- Canon SX720 vs Nikon D5100
- Canon T3i vs Nikon D5100
- Canon T5 vs Sony A850
- Fujifilm X100F vs Nikon D5100
- Fujifilm XF10 vs Sony A850
- Nikon D5100 vs Panasonic G5
- Nikon D5100 vs Panasonic GF5
- Nikon D5100 vs Sony A7R II
- Olympus E-PL6 vs Sony A850
- Panasonic S1 vs Sony A850
Specifications: Nikon D5100 vs Sony A850
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||Sony A850|
|Camera Type||Digital single lens reflex||Digital single lens reflex|
|Camera Lens||Nikon F mount lenses||Sony A mount lenses|
|Launch Date||April 2011||August 2009|
|Launch Price||USD 749||USD 1,999|
|Sensor Specs||Nikon D5100||Sony A850|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||23.6 x 15.7 mm||35.9 x 24.0 mm|
|Sensor Area||370.52 mm2||861.6 mm2|
|Sensor Diagonal||28.3 mm||43.2 mm|
|Sensor Resolution||16.1 Megapixels||24.4 Megapixels|
|Image Resolution||4928 x 3264 pixels||6048 x 4032 pixels|
|Pixel Pitch||4.80 μm||5.94 μm|
|Pixel Density||4.34 MP/cm2||2.83 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||1080/30p Video||no Video|
|ISO Setting||100 - 6,400 ISO||200 - 3,200 ISO|
|ISO Boost||100 - 25,600 ISO||100 - 6,400 ISO|
|Image Processor||EXPEED 2||BIONZ|
|DXO Sensor Quality (score)||80||79|
|DXO Color Depth (bits)||23.5||23.8|
|DXO Dynamic Range (EV)||13.6||12.2|
|DXO Low Light (ISO)||1183||1415|
|Screen Specs||Nikon D5100||Sony A850|
|Viewfinder Type||Optical viewfinder||Optical viewfinder|
|Viewfinder Field of View||95%||98%|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||921k dots||922k dots|
|LCD Attachment||Swivel screen||Fixed screen|
|Shooting Specs||Nikon D5100||Sony A850|
|Focus System||Phase-detect AF||Phase-detect AF|
|Continuous Shooting||4 shutter flaps/s||3 shutter flaps/s|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Built-in Flash||no On-Board Flash|
|Storage Medium||SDXC cards||CF or MS cards|
|Second Storage Option||Single card slot||Dual card slots|
|Connectivity Specs||Nikon D5100||Sony A850|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||mini HDMI||mini HDMI|
|Microphone Port||External MIC port||no MIC socket|
|Wifi Support||no Wifi||no Wifi|
|Body Specs||Nikon D5100||Sony A850|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||660 shots per charge||880 shots per charge|
128 x 97 x 79 mm
(5.0 x 3.8 x 3.1 in)
156 x 117 x 82 mm
(6.1 x 4.6 x 3.2 in)
|Camera Weight||560 g (19.8 oz)||895 g (31.6 oz)|
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