Pentax K-30 vs Sony A77
The Pentax K-30 and the Sony Alpha SLT-A77 are two digital cameras that were announced, respectively, in May 2012 and August 2011. Both are DSLR (Digital Single Lens Reflex) cameras that are equipped with an APS-C sensor. The Pentax has a resolution of 16.1 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.
Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-30 and the Sony Alpha SLT-A77? 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 Pentax K-30 and the Sony A77 are illustrated 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 width, height and depth dimensions are rounded to the nearest millimeter.
The K-30 can be obtained in seven different colors (black, silver, blue, red, yellow, green, white), while the A77 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 A77 is notably larger (18 percent) than the Pentax K-30. Moreover, the A77 is markedly heavier (13 percent) than the K-30. In this context, it is worth noting that both cameras are splash and dust-proof and can, hence, be used in inclement weather conditions or harsh environments.
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. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.
|1.||Pentax K-30||130 mm||97 mm||71 mm||650 g||410||Y||May 2012||849|
|2.||Sony A77||143 mm||104 mm||81 mm||732 g||470||Y||Aug 2011||1,399|
|3.||Nikon Df||144 mm||110 mm||67 mm||760 g||1400||Y||Nov 2013||2,749|
|4.||Olympus E-M1||130 mm||94 mm||63 mm||497 g||350||Y||Sep 2013||1,399|
|5.||Panasonic GH5||139 mm||98 mm||87 mm||725 g||410||Y||Jan 2017||1,999|
|6.||Panasonic GX7||123 mm||71 mm||55 mm||402 g||350||n||Aug 2013||999|
|7.||Pentax K-S2||123 mm||91 mm||73 mm||678 g||410||Y||Feb 2015||749|
|8.||Pentax K-S1||121 mm||93 mm||70 mm||558 g||410||n||Aug 2014||749|
|9.||Pentax K-50||130 mm||97 mm||71 mm||650 g||410||Y||Jun 2013||599|
|10.||Pentax K-500||130 mm||97 mm||71 mm||646 g||710||n||Jun 2013||549|
|11.||Pentax K-3||131 mm||100 mm||77 mm||800 g||560||Y||Oct 2013||1,299|
|12.||Pentax K-5 II||131 mm||97 mm||73 mm||760 g||740||Y||Sep 2012||1,099|
|13.||Pentax K-5||131 mm||97 mm||73 mm||760 g||740||Y||Sep 2010||1,099|
|14.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|15.||Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|16.||Sony A77 II||143 mm||104 mm||81 mm||647 g||480||Y||May 2014||1,199|
|17.||Sony A99||147 mm||111 mm||78 mm||812 g||500||Y||Sep 2012||2,799|
|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 K-30 was launched at a markedly lower price (by 39 percent) than the A77, 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. 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 A77 is 1 percent smaller. 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.
Technology-wise, both cameras are equipped with CMOS (Complementary Metal–Oxide–Semiconductor) sensors.
Despite having a slightly smaller sensor, the A77 offers a higher resolution of 24 megapixels, compared with 16.1 MP of the K-30. 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 3.91μm versus 4.79μm for the K-30). Moreover, it should be noted that the K-30 is a somewhat more recent model (by 8 months) than the A77, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels.
The resolution advantage of the Sony A77 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A77 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 Pentax K-30 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 Pentax K-30 has a native sensitivity range from ISO 100 to ISO 12800, which can be extended to ISO 100-25600. The corresponding ISO settings for the Sony Alpha SLT-A77 are ISO 100 to ISO 16000, with the possibility to increase the ISO range to 50-25600.
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 table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
| DXO |
|3.||Nikon Df||Full Frame||16.2||4928||3280||none||24.6||13.1||3279||89|
|4.||Olympus E-M1||Four Thirds||15.9||4608||3456||1080/30p||23.0||12.7||757||73|
|5.||Panasonic GH5||Four Thirds||20.2||5184||3888||4K/60p||23.9||13.0||807||77|
|6.||Panasonic GX7||Four Thirds||15.8||4592||3448||1080/60p||22.6||12.2||718||70|
|12.||Pentax K-5 II||APS-C||16.1||4928||3264||1080/25p||23.8||14.1||1235||82|
|14.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|15.||Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|16.||Sony A77 II||APS-C||24.0||6000||4000||1080/60p||..||..||..||..|
|17.||Sony A99||Full Frame||24.0||6000||4000||1080/60p||25.0||14.0||1555||89|
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 A77 provides a faster frame rate than the K-30. It can shoot movie footage at 1080/60p, while the Pentax is limited to 1080/30p.
Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A77 has an electronic viewfinder (2359k dots), while the K-30 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 viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the A77 has a higher magnification than the one of the K-30 (0.73x vs 0.61x), 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 Pentax K-30, the Sony A77, and comparable cameras.
|12.||Pentax K-5 II||optical||Y||3.0||921||fixed||n||1/8000s||7.0||Y||Y|
|15.||Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
|16.||Sony A77 II||2359||Y||3.0||1229||full-flex||n||1/8000s||12.0||Y||Y|
One feature that is present on the A77, but is missing on the K-30 is a top-level LCD. While being, of course, smaller than the rear screen, the control panel conveys some of the essential shooting information and can be convenient for quick and easy settings verification.The A77 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 K-30 does not have a selfie-screen.
The K-30 writes its imaging data to SDXC cards, while the A77 uses SDXC or Memory Stick PRO Duo cards. The A77 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the K-30 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 Pentax K-30 and Sony Alpha SLT-A77 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|12.||Pentax K-5 II||Y||stereo||mono||Y||-||mini||2.0||-||-||-|
|15.||Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|16.||Sony A77 II||Y||stereo||mono||Y||-||mini||2.0||Y||Y||-|
It is notable that the A77 has a microphone port, which can help to improve the quality of audio recordings by attaching an external microphone. The K-30 does not feature such a mic input.
Studio photographers will appreciate that the Sony A77 (unlike the K-30) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Travel and landscape photographers will find it useful that the A77 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.
Both the K-30 and the A77 have been discontinued, but can regularly be found used on eBay. The A77 was replaced by the Sony A77 II, while the K-30 was followed by the Pentax K-50. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Pentax and Sony websites.
So what is the bottom line? Is there a clear favorite between the Pentax K-30 and the Sony A77? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.
Reasons to prefer the Pentax K-30:
- Better low-light sensitivity: Requires less light for good images (0.5 stops ISO advantage).
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- More compact: Is smaller (130x97mm vs 143x104mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 82g or 11 percent) and hence easier to carry around.
- More affordable: Was introduced into a lower priced category (39 percent cheaper at launch).
- More modern: Is somewhat more recent (announced 8 months after the A77).
Arguments in favor of the Sony Alpha SLT-A77:
- More detail: Has more megapixels (24 vs 16.1MP), which boosts linear resolution by 22%.
- Better video: Provides higher movie framerates (1080/60p versus 1080/30p).
- Better sound: Can connect to an external microphone for higher quality sound recording.
- More framing info: Has an electronic viewfinder that displays shooting data.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.73x vs 0.61x).
- Easier setting verification: Features a control panel on top to check shooting parameters.
- More flexible LCD: Has a full-flex 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 (1/8000s vs 1/6000s) to freeze action.
- Faster burst: Shoots at higher frequency (12 vs 6 flaps/sec) to capture the decisive moment.
- Longer lasting: Gets more shots (470 versus 410) out of a single battery charge.
- Easier geotagging: Features an internal GPS sensor to log localization data.
- Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
- Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
- More heavily discounted: Has been on the market for longer (launched in August 2011).
If the count of individual advantages (bullet points above) is taken as a guide, the A77 is the clear winner of the contest (15 : 6 points). However, the relevance of individual strengths will vary across photographers, so that you might want to apply your own weighing scheme to the summary points when reflecting and deciding on a new camera. A professional wedding photographer will view the differences between cameras in a way that diverges from the perspective of a travel photog, and a person interested in cityscapes has distinct needs from a macro 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 Pentax K-30 and the Sony A77 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it says little about, for example, the shooting experience and imaging performance of the K-30 and the A77 in practical situations. 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 where reviews by experts come in. 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.||Pentax K-30||4/5||..||78/100||4.5/5||4.5/5||May 2012||849|
|2.||Sony A77||5/5||91/100||81/100||..||5/5||Aug 2011||1,399|
|3.||Nikon Df||4/5||..||81/100||4/5||4/5||Nov 2013||2,749|
|4.||Olympus E-M1||5/5||+ +||84/100||4.5/5||4.5/5||Sep 2013||1,399|
|5.||Panasonic GH5||4.5/5||+ +||85/100||4.5/5||5/5||Jan 2017||1,999|
|6.||Panasonic GX7||4/5||+||79/100||5/5||5/5||Aug 2013||999|
|7.||Pentax K-S2||4.5/5||..||..||5/5||4.5/5||Feb 2015||749|
|8.||Pentax K-S1||4/5||..||..||4.5/5||4/5||Aug 2014||749|
|9.||Pentax K-50||5/5||..||..||5/5||4.5/5||Jun 2013||599|
|10.||Pentax K-500||..||..||..||4.5/5||4.5/5||Jun 2013||549|
|11.||Pentax K-3||4/5||..||83/100||5/5||5/5||Oct 2013||1,299|
|12.||Pentax K-5 II||5/5||..||80/100||5/5||4.5/5||Sep 2012||1,099|
|13.||Pentax K-5||4/5||..||83/100||5/5||4.5/5||Sep 2010||1,099|
|14.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|15.||Sony A7 II||5/5||+||82/100||4.5/5||5/5||Nov 2014||1,999|
|16.||Sony A77 II||4/5||..||80/100||4.5/5||5/5||May 2014||1,199|
|17.||Sony A99||5/5||..||84/100||4.5/5||4.5/5||Sep 2012||2,799|
|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. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date 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 would like to check on the differences and similarities of other camera models, just make your choice using the following search menu. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Pentax K-30 vs Sony A77
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||Pentax K-30||Sony A77|
|Camera Type||Digital single lens reflex||Digital single lens reflex|
|Camera Lens||Pentax K mount lenses||Sony A mount lenses|
|Launch Date||May 2012||August 2011|
|Launch Price||USD 849||USD 1,399|
|Sensor Specs||Pentax K-30||Sony A77|
|Sensor Format||APS-C Sensor||APS-C Sensor|
|Sensor Size||23.7 x 15.6 mm||23.5 x 15.6 mm|
|Sensor Area||369.72 mm2||366.6 mm2|
|Sensor Diagonal||28.4 mm||28.2 mm|
|Sensor Resolution||16.1 Megapixels||24 Megapixels|
|Image Resolution||4928 x 3264 pixels||6000 x 4000 pixels|
|Pixel Pitch||4.79 μm||3.91 μm|
|Pixel Density||4.35 MP/cm2||6.55 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||1080/30p Video||1080/60p Video|
|ISO Setting||100 - 12,800 ISO||100 - 16,000 ISO|
|ISO Boost||100 - 25,600 ISO||50 - 25,600 ISO|
|Image Processor||PRIME M||BIONZ X|
|DXO Sensor Quality (score)||79||78|
|DXO Color Depth (bits)||23.7||24.0|
|DXO Dynamic Range (EV)||13.0||13.2|
|DXO Low Light (ISO)||1129||801|
|Screen Specs||Pentax K-30||Sony A77|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2359k dots|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||921k dots||921k dots|
|LCD Attachment||Fixed screen||Fully flexible screen|
|Shooting Specs||Pentax K-30||Sony A77|
|Focus System||Phase-detect AF||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/6000s||1/8000s|
|Continuous Shooting||6 shutter flaps/s||12 shutter flaps/s|
|Image Stabilization||In-body stabilization||In-body stabilization|
|Fill Flash||Built-in Flash||Built-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||Pentax K-30||Sony A77|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||no HDMI||mini HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Wifi Support||no Wifi||no Wifi|
|Geotagging||no internal GPS||GPS built-in|
|Body Specs||Pentax K-30||Sony A77|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||410 shots per charge||470 shots per charge|
130 x 97 x 71 mm
(5.1 x 3.8 x 2.8 in)
143 x 104 x 81 mm
(5.6 x 4.1 x 3.2 in)
|Camera Weight||650 g (22.9 oz)||732 g (25.8 oz)|
Did you notice an error on this page? If so, please get in touch, so that we can correct the information.