Pentax K-3 II vs Sony A99
The Pentax K-3 II and the Sony Alpha SLT-A99 are two digital cameras that were announced, respectively, in April 2015 and September 2012. Both are DSLR (Digital Single Lens Reflex) cameras that are based on an APS-C (K-3 II) and a full frame (A99) sensor. The Pentax has a resolution of 24.1 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.
|Pentax K-3 II||Sony A99|
|Digital single lens reflex||Digital single lens reflex|
|Pentax K mount lenses||Sony A mount lenses|
|24.1 MP, APS-C Sensor||24 MP, Full Frame Sensor|
|1080/60i Video||1080/60p Video|
|ISO 100-51200||ISO 100-25600|
|Optical viewfinder||Electronic viewfinder (2359k dots)|
|3.2" LCD, 1037k dots||3.0" LCD, 1229k dots|
|Fixed screen (not touch-sensitive)||Fully flexible screen (no touchscreen)|
|8.3 shutter flaps per second||6 shutter flaps per second|
|In-body stabilization||In-body stabilization|
|Weathersealed body||Weathersealed body|
|720 shots per battery charge||500 shots per battery charge|
|131 x 100 x 77 mm, 800 g||147 x 111 x 78 mm, 812 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-3 II and the Sony Alpha SLT-A99? 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-3 II and the Sony A99 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 dimensions are rounded to the nearest millimeter.
The K-3 II can be obtained in two different colors (black, silver), while the A99 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 A99 is notably larger (25 percent) than the Pentax K-3 II. Moreover, the A99 is slightly heavier (1 percent) than the K-3 II. 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 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, just use the right or left arrows in the table to switch to the respective camera. Alternatively, you can also navigate to the CAM-parator app and make your selection from the full list of cameras there.
|Pentax K-3 II»||131 mm||100 mm||77 mm||800 g||720||Y||Apr 2015||1,099||Pentax K-3 II|
|Sony A99«||147 mm||111 mm||78 mm||812 g||500||Y||Sep 2012||2,799||Sony A99|
|Canon 80D« »||139 mm||105 mm||79 mm||730 g||960||Y||Feb 2016||1,199||Canon 80D|
|Nikon D7500« »||136 mm||104 mm||73 mm||720 g||950||Y||Apr 2017||1,299||Nikon D7500|
|Nikon D7200« »||136 mm||107 mm||76 mm||765 g||1110||Y||Mar 2015||1,199||Nikon D7200|
|Panasonic GH5« »||139 mm||98 mm||87 mm||725 g||410||Y||Jan 2017||1,999||Panasonic GH5|
|Panasonic GX8« »||133 mm||78 mm||63 mm||487 g||330||Y||Jul 2015||1,199||Panasonic GX8|
|Pentax KP« »||132 mm||101 mm||76 mm||703 g||390||Y||Jan 2017||1,099||Pentax KP|
|Pentax K-70« »||126 mm||93 mm||74 mm||688 g||410||Y||Jun 2016||649||Pentax K-70|
|Pentax K-3« »||131 mm||100 mm||77 mm||800 g||560||Y||Oct 2013||1,299||Pentax K-3|
|Pentax K-5« »||131 mm||97 mm||73 mm||760 g||740||Y||Sep 2010||1,099||Pentax K-5|
|Sony A9« »||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499||Sony A9|
|Sony A99 II« »||143 mm||104 mm||76 mm||849 g||490||Y||Sep 2016||3,199||Sony A99 II|
|Sony RX10 II« »||129 mm||88 mm||102 mm||813 g||400||Y||Jun 2015||1,299||Sony RX10 II|
|Sony A77« »||143 mm||104 mm||81 mm||732 g||470||Y||Aug 2011||1,399||Sony A77|
|Sony A850« »||156 mm||117 mm||82 mm||895 g||880||Y||Aug 2009||1,999||Sony A850|
|Sony A900« »||156 mm||117 mm||82 mm||895 g||880||Y||Sep 2008||2,999||Sony A900|
|Note: Measurements and pricing do not include easily detachable parts, such as interchangeable lenses or optional viewfinders.|
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 K-3 II was launched at a markedly lower price (by 61 percent) than the A99, which puts it into a different market segment. 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. 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 associated with larger, more expensive camera bodies and lenses.
Of the two cameras under consideration, the Pentax K-3 II features an APS-C sensor and the Sony A99 a full frame sensor. The sensor area in the A99 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.
Despite having a smaller sensor, the Pentax K-3 II offers a higher resolution of 24.1 megapixels, compared with 24 MP of the Sony A99. 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 3.90μm versus 5.96μm for the A99). However, it should be noted that the K-3 II is much more recent (by 2 years and 7 months) than the A99, 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 K-3 II has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
Unlike the A99, the K-3 II 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 Pentax K-3 II has a native sensitivity range from ISO 100 to ISO 51200. The corresponding ISO settings for the Sony Alpha SLT-A99 are ISO 100 to ISO 25600, with the possibility to increase the ISO range to 50-25600.
Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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"). Of the two cameras under consideration, the A99 has a markedly higher DXO score than the K-3 II (overall score 9 points higher), which will translate into better image quality. The advantage is based on 1.4 bits higher color depth, 0.4 EV in additional dynamic range, and 0.5 stops in additional low light sensitivity. The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.
|Pentax K-3 II||APS-C||24.1||6016||4000||1080/60i||23.6||13.6||1106||80||Pentax K-3 II|
|Sony A99||Full Frame||24.0||6000||4000||1080/60p||25.0||14.0||1555||89||Sony A99|
|Canon 80D||APS-C||24.0||6000||4000||1080/60p||23.6||13.2||1135||79||Canon 80D|
|Nikon D7500||APS-C||20.7||5568||3712||4K/30p||24.3||14.0||1483||86||Nikon D7500|
|Nikon D7200||APS-C||24.0||6000||4000||1080/60p||24.5||14.6||1333||87||Nikon D7200|
|Panasonic GH5||Four Thirds||20.2||5184||3888||4K/60p||23.9||13.0||807||77||Panasonic GH5|
|Panasonic GX8||Four Thirds||20.2||5184||3888||4K/30p||23.5||12.6||806||75||Panasonic GX8|
|Pentax KP||APS-C||24.1||6016||4000||1080/60i||..||..||..||..||Pentax KP|
|Pentax K-70||APS-C||24.0||6000||4000||1080/60i||..||..||..||..||Pentax K-70|
|Pentax K-3||APS-C||24.1||6016||4000||1080/60i||23.7||13.4||1216||80||Pentax K-3|
|Pentax K-5||APS-C||16.1||4928||3264||1080/25p||23.7||14.1||1162||82||Pentax K-5|
|Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92||Sony A9|
|Sony A99 II||Full Frame||42.2||7952||5304||4K/30p||25.4||13.4||2317||92||Sony A99 II|
|Sony RX10 II||1-inch||20.0||5472||3648||4K/30p||23.0||12.6||531||70||Sony RX10 II|
|Sony A77||APS-C||24.0||6000||4000||1080/60p||24.0||13.2||801||78||Sony A77|
|Sony A850||Full Frame||24.4||6048||4032||none||23.8||12.2||1415||79||Sony A850|
|Sony A900||Full Frame||24.4||6048||4032||none||23.7||12.3||1431||79||Sony A900|
Many modern cameras are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the A99 provides a faster frame rate than the K-3 II. It can shoot movie footage at 1080/60p, while the Pentax is limited to 1080/60i.
Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A99 has an electronic viewfinder (2359k dots), while the K-3 II 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 A99 has a higher magnification than the one of the K-3 II (0.71x vs 0.63x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The adjacent table lists some of the other core features of the Pentax K-3 II and Sony A99 along with similar information for a selection of comparators.
|Pentax K-3 II||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||n||Y||Pentax K-3 II|
|Sony A99||2359||Y||3.0||1229||full-flex||n||1/8000s||6.0||n||Y||Sony A99|
|Canon 80D||optical||Y||3.0||1040||swivel||Y||1/8000s||7.0||Y||n||Canon 80D|
|Nikon D7500||optical||Y||3.2||922||tilting||Y||1/8000s||8.0||Y||n||Nikon D7500|
|Nikon D7200||optical||Y||3.2||1229||fixed||n||1/8000s||6.0||Y||n||Nikon D7200|
|Panasonic GH5||3680||n||3.2||1620||swivel||Y||1/8000s||12.0||n||Y||Panasonic GH5|
|Panasonic GX8||2360||n||3.0||1040||swivel||Y||1/8000s||10.0||n||Y||Panasonic GX8|
|Pentax KP||optical||n||3.0||921||tilting||n||1/6000s||7.0||Y||Y||Pentax KP|
|Pentax K-70||optical||n||3.0||921||swivel||n||1/6000s||6.0||Y||Y||Pentax K-70|
|Pentax K-3||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||Y||Y||Pentax K-3|
|Pentax K-5||optical||Y||3.0||921||fixed||n||1/8000s||7.0||Y||Y||Pentax K-5|
|Sony A9||3686||n||3.0||1440||tilting||Y||1/8000s||20.0||n||Y||Sony A9|
|Sony A99 II||2400||Y||3.0||1229||full-flex||n||1/8000s||12.0||n||Y||Sony A99 II|
|Sony RX10 II||2359||Y||3.0||1229||tilting||n||1/3200s||14.0||Y||Y||Sony RX10 II|
|Sony A77||2359||Y||3.0||921||full-flex||n||1/8000s||12.0||Y||Y||Sony A77|
|Sony A850||optical||Y||3.0||922||fixed||n||1/8000s||3.0||n||Y||Sony A850|
|Sony A900||optical||Y||3.0||922||fixed||n||1/8000s||5.0||n||Y||Sony A900|
The Pentax K-3 II 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 K-3 II writes its imaging data to SDXC cards, while the A99 uses SDXC or Memory Stick PRO Duo cards. The K-3 II features dual card slots, which can be very useful in case a memory card fails. In contrast, the A99 only has one slot. Both cameras can use UHS-I cards, which provide for Ultra High Speed data transfer of up to 104 MB/s.
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-3 II and Sony Alpha SLT-A99 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
|Pentax K-3 II||Y||mono||mono||Y||Y||mini||3.0||-||-||-||Pentax K-3 II|
|Sony A99||Y||stereo||mono||Y||Y||mini||2.0||-||-||-||Sony A99|
|Canon 80D||Y||stereo||mono||Y||Y||mini||2.0||Y||Y||-||Canon 80D|
|Nikon D7500||Y||stereo||mono||Y||Y||mini||2.0||Y||-||Y||Nikon D7500|
|Nikon D7200||Y||stereo||mono||Y||Y||mini||2.0||Y||Y||-||Nikon D7200|
|Panasonic GH5||Y||stereo||mono||Y||Y||full||3.1||Y||-||Y||Panasonic GH5|
|Panasonic GX8||Y||stereo||mono||Y||-||micro||2.0||Y||Y||-||Panasonic GX8|
|Pentax KP||Y||stereo||mono||Y||-||none||2.0||Y||-||-||Pentax KP|
|Pentax K-70||Y||stereo||mono||Y||-||mini||2.0||Y||-||-||Pentax K-70|
|Pentax K-3||Y||mono||mono||Y||Y||mini||3.0||-||-||-||Pentax K-3|
|Pentax K-5||Y||stereo||mono||Y||-||mini||2.0||-||-||-||Pentax K-5|
|Sony A9||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||Y||Sony A9|
|Sony A99 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||Y||Sony A99 II|
|Sony RX10 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-||Sony RX10 II|
|Sony A77||Y||stereo||mono||Y||-||mini||2.0||-||-||-||Sony A77|
|Sony A850||Y||none||none||-||-||mini||2.0||-||-||-||Sony A850|
|Sony A900||Y||none||none||-||-||mini||2.0||-||-||-||Sony A900|
Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.
Travel and landscape photographers will find it useful that both cameras feature internal geolocalization sensors and can record GPS coordinates in their EXIF data.
The K-3 II is a recent model that features in the current product line-up of Pentax. In contrast, the A99 has been discontinued (but it can be found pre-owned on eBay). As a replacement in the same line of cameras, the A99 was succeeded by the Sony A99 II. 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 conclusions can be drawn? Is the Pentax K-3 II better than the Sony A99 or vice versa? The listing below highlights the relative strengths of the two models.
Advantages of the Pentax K-3 II:
- 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.
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
- Faster burst: Shoots at higher frequency (8.3 vs 6 flaps/sec) to capture the decisive moment.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More compact: Is smaller (131x100mm vs 147x111mm) and thus needs less room in the bag.
- Longer lasting: Can take more shots (720 versus 500) on a single battery charge.
- Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
- Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
- More affordable: Was introduced into a lower priced category (61 percent cheaper at launch).
- More modern: Reflects 2 years and 7 months of technical progress since the A99 launch.
Arguments in favor of the Sony Alpha SLT-A99:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better image quality: Scores markedly higher (9 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (1.4 bits more color depth).
- Better low-light sensitivity: Can shoot in dim conditions (0.5 stops ISO advantage).
- Better video: Provides higher movie framerates (1080/60p versus 1080/60i).
- More framing info: Has an electronic viewfinder that displays shooting data.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.71x vs 0.63x).
- More detailed LCD: Has a higher resolution rear screen (1229k vs 1037k dots).
- 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.
- More heavily discounted: Has been around for much longer (launched in September 2012).
If the number of relative strengths (bullet points above) is taken as a guide, the K-3 II comes out slightly ahead of the A99 (12 : 11 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 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-3 II and the Sony A99 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 remains incomplete and does no justice, for example, to the way the K-3 II or the A99 perform in practice. 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 hands-on reviews by experts are important. The table below provides a synthesis of the camera assessments of some of the best known photo-gear 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.
The review scores listed above should be treated with care, 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 comparing ratings of very distinct cameras or ones that are far apart in terms of their release date 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
Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just use the search menu below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
- Canon 1Ds vs Pentax K-3 II
- Fujifilm X100T vs Pentax K-3 II
- Hasselblad X1D vs Sony A99
- Nikon D200 vs Sony A99 II
- Olympus E-30 vs Sony A99
- Olympus E-520 vs Pentax K-3 II
- Olympus E-M10 III vs Sony A99 II
- Olympus E-P2 vs Pentax K-3 II
- Panasonic LX15 vs Sony A99 II
- Pentax K-3 II vs Sony A900
- Pentax K-3 II vs Sony HX95
- Pentax K-3 II vs Sony RX100 V
Specifications: Pentax K-3 II vs Sony A99
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-3 II||Sony A99|
|Camera Type||Digital single lens reflex||Digital single lens reflex|
|Camera Lens||Pentax K mount lenses||Sony A mount lenses|
|Launch Date||April 2015||September 2012|
|Launch Price||USD 1099||USD 2799|
|Sensor Specs||Pentax K-3 II||Sony A99|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||23.5 x 15.6 mm||35.8 x 23.8 mm|
|Sensor Area||366.6 mm2||852.04 mm2|
|Sensor Diagonal||28.2 mm||43 mm|
|Sensor Resolution||24.1 Megapixels||24 Megapixels|
|Image Resolution||6016 x 4000 pixels||6000 x 4000 pixels|
|Pixel Pitch||3.90 μm||5.96 μm|
|Pixel Density||6.56 MP/cm2||2.82 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||1080/60i Video||1080/60p Video|
|ISO Setting||100-51200 ISO||100-25600 ISO|
|ISO Boost||no Enhancement||50-25600 ISO|
|Image Processor||PRIME III||BIONZ X|
|DXO Sensor Quality (score)||80||89|
|DXO Color Depth (bits)||23.6||25.0|
|DXO Dynamic Range (EV)||13.6||14.0|
|DXO Low Light (ISO)||1106||1555|
|Screen Specs||Pentax K-3 II||Sony A99|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||100%||100%|
|Viewfinder Resolution||2359k dots|
|Top-Level Screen||Control Panel||Control Panel|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.2 inch||3.0 inch|
|LCD Resolution||1037k dots||1229k dots|
|LCD Attachment||Fixed screen||Fully flexible screen|
|Shooting Specs||Pentax K-3 II||Sony A99|
|Focus System||Phase-detect AF||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000/s||1/8000/s|
|Continuous Shooting||8.3 shutter flaps/s||6 shutter flaps/s|
|Shutter Life Expectancy||200 000 actuations||200 000 actuations|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||In-body stabilization||In-body stabilization|
|Fill Flash||no On-Board Flash||no On-Board Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Dual card slots||Single card slot|
|UHS card support||UHS-I||UHS-I|
|Connectivity Specs||Pentax K-3 II||Sony A99|
|Studio Flash||PC Sync socket||PC Sync socket|
|USB Connector||USB 3.0||USB 2.0|
|HDMI Port||mini HDMI||mini HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||Headphone port||Headphone port|
|Wifi Support||no Wifi||no Wifi|
|Geotagging||GPS built-in||GPS built-in|
|Body Specs||Pentax K-3 II||Sony A99|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||720 shots per charge||500 shots per charge|
131 x 100 x 77 mm
(5.2 x 3.9 x 3.0 in)
147 x 111 x 78 mm
(5.8 x 4.4 x 3.1 in)
|Camera Weight||800 g (28.2 oz)||812 g (28.6 oz)|
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