Nikon D3100 vs Sony A68
The Nikon D3100 and the Sony Alpha SLT-A68 are two digital cameras that were officially introduced, respectively, in August 2010 and November 2015. Both are DSLR (Digital Single Lens Reflex) cameras that are equipped with an APS-C sensor. The Nikon has a resolution of 14.2 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.
|Nikon D3100||Sony A68|
|Digital single lens reflex||Digital single lens reflex|
|Nikon F mount lenses||Sony A mount lenses|
|14.2 MP, APS-C Sensor||24 MP, APS-C Sensor|
|1080/24p Video||1080/60i Video|
|ISO 100-3,200 (100 - 12,800)||ISO 100-25,600|
|Optical viewfinder||Electronic viewfinder (1440k dots)|
|3.0 LCD, 230k dots||2.7 LCD, 460k dots|
|Fixed screen (not touch-sensitive)||Tilting screen (not touch-sensitive)|
|3 shutter flaps per second||8 shutter flaps per second|
|Lens stabilization only||In-body stabilization|
|550 shots per battery charge||540 shots per battery charge|
|124 x 96 x 75 mm, 505 g||143 x 104 x 81 mm, 610 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Nikon D3100 and the Sony Alpha SLT-A68? 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 Nikon D3100 and the Sony A68. 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.
The D3100 can be obtained in two different colors (black, red), while the A68 is only available in black.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A68 is notably larger (25 percent) than the Nikon D3100. Moreover, the A68 is markedly heavier (21 percent) than the D3100. In this context, it is worth noting that neither the D3100 nor the A68 are weather-sealed.
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 adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. If you want to switch the focus of the display and review another camera pair, just select a new right or left comparator from among the camera models in the table. Alternatively, you can also move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|Nikon D3100||4.9 in||3.8 in||3.0 in||17.8 oz||550||n||Aug 2010||599|
|Sony A68||5.6 in||4.1 in||3.2 in||21.5 oz||540||n||Nov 2015||699|
|Nikon D3200||4.9 in||3.8 in||3.0 in||17.8 oz||540||n||Apr 2012||599|
|Nikon D5100||5.0 in||3.8 in||3.1 in||19.8 oz||660||n||Apr 2011||749|
|Nikon D7000||5.2 in||4.1 in||3.0 in||27.5 oz||1050||Y||Sep 2010||1,499|
|Nikon D3000||5.0 in||3.8 in||2.5 in||18.9 oz||500||n||Jul 2009||599|
|Nikon D5000||5.0 in||4.1 in||3.1 in||20.8 oz||510||n||Apr 2009||749|
|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|
|Nikon D40||4.9 in||3.7 in||2.5 in||18.4 oz||470||n||Nov 2006||499|
|Panasonic ZS100||4.4 in||2.6 in||1.7 in||11.0 oz||300||n||Jan 2016||699|
|Sony A77 II||5.6 in||4.1 in||3.2 in||22.8 oz||480||Y||May 2014||1,199|
|Sony A6000||4.7 in||2.6 in||1.8 in||12.1 oz||360||n||Feb 2014||599|
|Sony A58||5.1 in||3.7 in||3.1 in||17.4 oz||690||n||Feb 2013||599|
|Sony A77||5.6 in||4.1 in||3.2 in||25.8 oz||470||Y||Aug 2011||1,399|
|Sony NEX-5N||4.4 in||2.3 in||1.5 in||9.5 oz||460||n||Aug 2011||699|
|Sony NEX-C3||4.3 in||2.4 in||1.3 in||7.9 oz||400||n||Jun 2011||599|
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.
Any camera decision will naturally be influenced heavily by the price. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The D3100 was launched at a somewhat lower price (by 14 percent) than the A68, which makes it more attractive for photographers on a tight budget. 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 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. 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.
Both cameras under consideration feature an APS-C sensor, but their sensors differ slightly in size. The sensor area in the A68 is 3 percent bigger. They nevertheless have the same format factor of 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
In terms of underlying technology, both cameras are build around CMOS sensors.
With 24MP, the A68 offers a higher resolution than the D3100 (14.2MP), but the A68 has smaller individual pixels (pixel pitch of 3.91μm versus 5.01μm for the D3100). Yet, the A68 is a much more recent model (by 5 years and 2 months) than the D3100, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units.
The resolution advantage of the Sony A68 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A68 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 Nikon D3100 are 23 x 15.4 inches or 58.5 x 39 cm for good quality, 18.4 x 12.3 inches or 46.8 x 31.2 cm for very good quality, and 15.4 x 10.2 inches or 39 x 26 cm for excellent quality prints.
The Nikon D3100 has a native sensitivity range from ISO 100 to ISO 3200, which can be extended to ISO 100-12800. The corresponding ISO settings for the Sony Alpha SLT-A68 are ISO 100 to ISO 25600 (no boost).
Consistent information on actual sensor performance is available from DXO Mark for many cameras. This service is based on lab testing and assigns an overall score to each camera sensor, as well as ratings for dynamic range ("DXO Landscape"), color depth ("DXO Portrait"), and low-light sensitivity ("DXO Sports"). Of the two cameras under consideration, the A68 offers substantially better image quality than the D3100 (overall score 12 points higher). The advantage is based on 1.6 bits higher color depth, 2.2 EV in additional dynamic range, and 0.4 stops of reduced low light sensitivity. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
|Sony A77 II||APS-C||24.0||6000||4000||1080/60p||..||..||..||..|
Many modern cameras are not only capable of taking still images, but can also record movies. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the A68 provides a faster frame rate than the D3100. It can shoot movie footage at 1080/60i, while the Nikon is limited to 1080/24p.
Apart from body and sensor, cameras can and do differ across a range of features. For example, the A68 has an electronic viewfinder (1440k dots), while the D3100 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 A68 offers a wider field of view (100%) than the one in the D3100 (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the A68 has a higher magnification (0.57x vs 0.53x), 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 D3100 and Sony A68 in connection with corresponding information for a sample of similar cameras.
|Sony A77 II||2359||Y||3.0||1229||full-flex||n||1/8000s||12.0||Y||Y|
One feature that differentiates the A68 and the D3100 is in-body image stabilization (IBIS). The A68 reduces the risk of handshake-induced blur with all attached lenses, while the D3100 offers no blur reduction with lenses that themselves do not provide optical image stabilization.
The D3100 writes its imaging data to SDXC cards, while the A68 uses SDXC or Memory Stick PRO Duo cards. The A68 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the D3100 cannot take advantage of Ultra High Speed SD 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 D3100 and Sony Alpha SLT-A68 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
|Sony A77 II||Y||stereo||mono||Y||-||mini||2.0||Y||Y||-|
It is notable that the A68 has a microphone port, which can help to improve the quality of audio recordings by attaching an external microphone. The D3100 does not feature such a mic input.
Both the D3100 and the A68 have been discontinued, but can regularly be found used on eBay. The D3100 was replaced by the Nikon D3200, while the A68 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 how do things add up? Is the Nikon D3100 better than the Sony A68 or vice versa? Below is a summary of the relative strengths of each of the two contestants.
Reasons to prefer the Nikon D3100:
- Better low-light sensitivity: Requires less light for good images (0.4 stops ISO advantage).
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- Larger screen: Has a bigger rear LCD (3.0" vs 2.7") for image review and settings control.
- More compact: Is smaller (124x96mm vs 143x104mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 105g or 17 percent) and hence easier to carry around.
- More affordable: Was introduced into a lower priced segment (14 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in August 2010).
Advantages of the Sony Alpha SLT-A68:
- More detail: Has more megapixels (24 vs 14.2MP), which boosts linear resolution by 30%.
- Better image quality: Scores substantially higher (12 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (1.6 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (2.2 EV of extra DR).
- Better video: Provides higher movie framerates (1080/60i versus 1080/24p).
- Better sound: Can connect to an external microphone for higher quality sound 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 (0.57x vs 0.53x).
- Easier setting verification: Features a control panel on top to check shooting parameters.
- More detailed LCD: Has a higher resolution rear screen (460k vs 230k dots).
- More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
- Faster burst: Shoots at higher frequency (8 vs 3 flaps/sec) to capture the decisive moment.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
- More modern: Reflects 5 years and 2 months of technical progress since the D3100 launch.
If the count of individual advantages (bullet points above) is taken as a guide, the A68 is the clear winner of the contest (16 : 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 sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape 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 D3100 and the Sony A68 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 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 D3100 and the A68 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.
This is why expert reviews are important. The adjacent summary-table relays the overall verdicts of several of the most popular camera 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.
|Nikon D3100||+ +||72/100||4.5/5||5/5||4.5/5||Aug 2010||599|
|Sony A68||..||..||4/5||..||4/5||Nov 2015||699|
|Nikon D3200||+ +||73/100||4.5/5||4.5/5||4.5/5||Apr 2012||599|
|Nikon D5100||+ +||76/100||4.5/5||5/5||4.5/5||Apr 2011||749|
|Nikon D7000||..||80/100||4.5/5||5/5||4.5/5||Sep 2010||1,499|
|Nikon D3000||+||72/100||4/5||3.5/5||4.5/5||Jul 2009||599|
|Nikon D5000||+ +||75/100||4/5||5/5||4.5/5||Apr 2009||749|
|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|
|Nikon D40||81/100||+ +||o||5/5||4.5/5||Nov 2006||499|
|Panasonic ZS100||+ +||82/100||4.5/5||4/5||4.5/5||Jan 2016||699|
|Sony A77 II||..||80/100||4.5/5||4/5||5/5||May 2014||1,199|
|Sony A6000||+||80/100||4.5/5||5/5||5/5||Feb 2014||599|
|Sony A58||..||..||4.5/5||4.5/5||4.5/5||Feb 2013||599|
|Sony A77||91/100||81/100||..||4.5/5||5/5||Aug 2011||1,399|
|Sony NEX-5N||+ +||79/100||4.5/5||5/5||4.5/5||Aug 2011||699|
|Sony NEX-C3||+ +||74/100||4.5/5||4.5/5||4/5||Jun 2011||599|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The above review scores should be interpreted with care, though. The assessments were made in relation to similar cameras of the same technological generation. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, 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? If you would like to see a different side-by-side camera review, 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 G7 X Mark III vs Sony A68
- Contax N Digital vs Nikon D3100
- Fujifilm X-T100 vs Nikon D3100
- Fujifilm X100F vs Nikon D3100
- Fujifilm XP140 vs Nikon D3100
- Leica V-LUX 5 vs Nikon D3100
- Nikon D3100 vs Nikon W150
- Nikon D3100 vs Sony A6600
- Nikon D3100 vs Sony NEX-F3
- Olympus TG-5 vs Sony A68
- Panasonic TS7 vs Sony A68
- Sony A68 vs Sony HX350
Specifications: Nikon D3100 vs Sony A68
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 D3100||Sony A68|
|Camera Type||Digital single lens reflex||Digital single lens reflex|
|Camera Lens||Nikon F mount lenses||Sony A mount lenses|
|Launch Date||August 2010||November 2015|
|Launch Price||USD 599||USD 699|
|Sensor Specs||Nikon D3100||Sony A68|
|Sensor Format||APS-C Sensor||APS-C Sensor|
|Sensor Size||23.1 x 15.4 mm||23.5 x 15.6 mm|
|Sensor Area||355.74 mm2||366.6 mm2|
|Sensor Diagonal||27.8 mm||28.2 mm|
|Sensor Resolution||14.2 Megapixels||24 Megapixels|
|Image Resolution||4608 x 3072 pixels||6000 x 4000 pixels|
|Pixel Pitch||5.01 μm||3.91 μm|
|Pixel Density||3.98 MP/cm2||6.55 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||1080/24p Video||1080/60i Video|
|ISO Setting||100 - 3,200 ISO||100 - 25,600 ISO|
|ISO Boost||100 - 12,800 ISO||no Enhancement|
|Image Processor||EXPEED 2||BIONZ X|
|DXO Sensor Quality (score)||67||79|
|DXO Color Depth (bits)||22.5||24.1|
|DXO Dynamic Range (EV)||11.3||13.5|
|DXO Low Light (ISO)||919||701|
|Screen Specs||Nikon D3100||Sony A68|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||95%||100%|
|Viewfinder Resolution||1440k dots|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||2.7inch|
|LCD Resolution||230k dots||460k dots|
|LCD Attachment||Fixed screen||Tilting screen|
|Shooting Specs||Nikon D3100||Sony A68|
|Focus System||Phase-detect AF||Phase-detect AF|
|Manual Focusing Aid||no Peaking Feature||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/4000s|
|Continuous Shooting||3 shutter flaps/s||8 shutter flaps/s|
|Shutter Life Expectancy||100 000 actuations||100 000 actuations|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Build-in Flash||Build-in Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Single card slot||Single card slot|
|UHS card support||no||UHS-I|
|Connectivity Specs||Nikon D3100||Sony A68|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||mini HDMI||micro HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Wifi Support||no Wifi||no Wifi|
|Body Specs||Nikon D3100||Sony A68|
|Battery Life (CIPA)||550 shots per charge||540 shots per charge|
124 x 96 x 75 mm
(4.9 x 3.8 x 3.0 in)
143 x 104 x 81 mm
(5.6 x 4.1 x 3.2 in)
|Camera Weight||505 g (17.8 oz)||610 g (21.5 oz)|
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