Nikon D3100 vs Pentax K-70
The Nikon D3100 and the Pentax K-70 are two digital cameras that were officially introduced, respectively, in August 2010 and June 2016. 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 Pentax provides 24 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 D3100 and the Pentax K-70? 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 Pentax K-70. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All size dimensions are rounded to the nearest millimeter.
The D3100 can be obtained in two different colors (black, red), while the K-70 is also available in two color-versions, but different ones (black, silver).
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax K-70 is somewhat smaller (2 percent) than the Nikon D3100. However, the K-70 is substantially heavier (36 percent) than the D3100. It is noteworthy in this context that the K-70 is splash and dust-proof, while the D3100 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 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.
|Nikon D3100||4.9 in||3.8 in||3.0 in||17.8 oz||550||n||Aug 2010||599|
|Pentax K-70||5.0 in||3.7 in||2.9 in||24.3 oz||410||Y||Jun 2016||649|
|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|
|Pentax KP||5.2 in||4.0 in||3.0 in||24.8 oz||390||Y||Jan 2017||1,099|
|Pentax K-3 II||5.2 in||3.9 in||3.0 in||28.2 oz||720||Y||Apr 2015||1,099|
|Pentax K-3||5.2 in||3.9 in||3.0 in||28.2 oz||560||Y||Oct 2013||1,299|
|Pentax K-5||5.2 in||3.8 in||2.9 in||26.8 oz||740||Y||Sep 2010||1,099|
|Sony A68||5.6 in||4.1 in||3.2 in||21.5 oz||540||n||Nov 2015||699|
|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.|
The price is, of course, an important factor in any camera decision. 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 D3100 was somewhat cheaper (by 8 percent) than the K-70 at launch, but both cameras fall into the same price category. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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 imaging sensor is a crucial determinant of image quality. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and 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 K-70 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 K-70 offers a higher resolution than the D3100 (14.2MP), but the K-70 has smaller individual pixels (pixel pitch of 3.91μm versus 5.01μm for the D3100). Yet, the K-70 is a much more recent model (by 5 years and 9 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. Coming back to sensor resolution, it should be mentioned that the K-70 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Pentax K-70 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-70 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 K-70 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
Unlike the D3100, the K-70 has the capacity to capture high quality composite images 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 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 Pentax K-70 are ISO 100 to ISO 102400 (no boost).
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 table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
| DXO |
|Pentax K-3 II||APS-C||24.1||6016||4000||1080/60i||23.6||13.6||1106||80|
Many modern cameras are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the K-70 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 variety of features. The D3100 and the K-70 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 K-70 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 K-70 has a higher magnification (0.63x 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 Pentax K-70 in connection with corresponding information for a sample of similar cameras.
|Pentax K-3 II||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||n||Y|
One feature that differentiates the K-70 and the D3100 is in-body image stabilization (IBIS). The K-70 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 K-70 has an articulated screen that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in taking selfies. In contrast, the D3100 does not have a selfie-screen.
The Pentax K-70 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.
Concerning the storage of imaging data, both the D3100 and the K-70 write their files to SDXC cards. The K-70 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 Pentax K-70 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|Pentax K-3 II||Y||mono||mono||Y||Y||mini||3.0||-||-||-|
It is notable that the K-70 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the D3100 does not provide wifi capability.
The K-70 is a recent model that features in the current product line-up of Pentax. In contrast, the D3100 has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the D3100 was succeeded by the Nikon D3200. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Nikon and Pentax websites.
So how do things add up? Is the Nikon D3100 better than the Pentax K-70 or vice versa? Below is a summary of the relative strengths of each of the two contestants.
Advantages of the Nikon D3100:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Less heavy: Is lighter (by 183g or 27 percent) and hence easier to carry around.
- Longer lasting: Can take more shots (550 versus 410) on a single battery charge.
- More heavily discounted: Has been available for much longer (launched in August 2010).
Reasons to prefer the Pentax K-70:
- More detail: Has more megapixels (24 vs 14.2MP), which boosts linear resolution by 30%.
- 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 movie framerates (1080/60i versus 1080/24p).
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- Better sound: Can connect to an external microphone for higher quality sound recording.
- 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 (0.63x vs 0.53x).
- More detailed LCD: Has a higher resolution rear screen (921k vs 230k dots).
- 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 shutter: Has higher mechanical shutter speed (1/6000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (6 vs 3 flaps/sec) to capture the decisive moment.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- 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.
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
- More modern: Reflects 5 years and 9 months of technical progress since the D3100 launch.
If the count of relative strengths (bullet points above) is taken as a measure, the K-70 is the clear winner of the contest (19 : 4 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 Nikon D3100 and the Pentax K-70 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 partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the D3100 or the K-70. 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 hands-on reviews by experts 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|
|Pentax K-70||..||79/100||4.5/5||4/5||4.5/5||Jun 2016||649|
|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|
|Pentax KP||..||82/100||5/5||..||4.5/5||Jan 2017||1,099|
|Pentax K-3 II||..||..||5/5||4.5/5||5/5||Apr 2015||1,099|
|Pentax K-3||..||83/100||5/5||4.5/5||5/5||Oct 2013||1,299|
|Pentax K-5||..||83/100||5/5||4.5/5||4.5/5||Sep 2010||1,099|
|Sony A68||..||..||4/5||..||4/5||Nov 2015||699|
|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.|
Care should be taken when interpreting the review scores above, though. The ratings are only valid when referring to cameras in the same category and of the same age. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparisons of ratings among very different cameras or across long time periods have little meaning. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.
Other camera comparisons
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Specifications: Nikon D3100 vs Pentax K-70
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||Pentax K-70|
|Camera Type||Digital single lens reflex||Digital single lens reflex|
|Camera Lens||Nikon F mount lenses||Pentax K mount lenses|
|Launch Date||August 2010||June 2016|
|Launch Price||USD 599||USD 649|
|Sensor Specs||Nikon D3100||Pentax K-70|
|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||no AA filter|
|Movie Capability||1080/24p Video||1080/60i Video|
|ISO Setting||100 - 3,200 ISO||100 - 102,400 ISO|
|ISO Boost||100 - 12,800 ISO||no Enhancement|
|Image Processor||EXPEED 2||PRIME MII|
|DXO Sensor Quality (score)||67||..|
|DXO Color Depth (bits)||22.5||..|
|DXO Dynamic Range (EV)||11.3||..|
|DXO Low Light (ISO)||919||..|
|Screen Specs||Nikon D3100||Pentax K-70|
|Viewfinder Type||Optical viewfinder||Optical viewfinder|
|Viewfinder Field of View||95%||100%|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||230k dots||921k dots|
|LCD Attachment||Fixed screen||Swivel screen|
|Shooting Specs||Nikon D3100||Pentax K-70|
|Focus System||Phase-detect AF||Phase-detect AF|
|Manual Focusing Aid||no Peaking Feature||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/6000s|
|Continuous Shooting||3 shutter flaps/s||6 shutter flaps/s|
|Shutter Life Expectancy||100 000 actuations||100 000 actuations|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Build-in Flash||Build-in Flash|
|Storage Medium||SDXC cards||SDXC cards|
|Second Storage Option||Single card slot||Single card slot|
|UHS card support||no||UHS-I|
|Connectivity Specs||Nikon D3100||Pentax K-70|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||mini HDMI||mini HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Wifi Support||no Wifi||Wifi built-in|
|Body Specs||Nikon D3100||Pentax K-70|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||550 shots per charge||410 shots per charge|
124 x 96 x 75 mm
(4.9 x 3.8 x 3.0 in)
126 x 93 x 74 mm
(5.0 x 3.7 x 2.9 in)
|Camera Weight||505 g (17.8 oz)||688 g (24.3 oz)|
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