Canon G3 X vs Pentax K-3 II
The Canon PowerShot G3 X and the Pentax K-3 II are two digital cameras that were revealed to the public, respectively, in June 2015 and April 2015. The G3X is a fixed lens compact, while the K-3 II is a DSLR. The cameras are based on an one-inch (G3X) and an APS-C (K-3 II) sensor. The Canon has a resolution of 20 megapixels, whereas the Pentax provides 24.1 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 Canon PowerShot G3 X and the Pentax K-3 II? 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 Canon G3 X and the Pentax K-3 II 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 width, height and depth measures are rounded to the nearest millimeter.
The K-3 II can be obtained in two different colors (black, silver), while the G3X 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 Pentax K-3 II is notably larger (38 percent) than the Canon G3 X. 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 and possibly misleading, as the G3X has a lens built in, whereas the K-3 II is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup.
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.||Canon G3 X||123 mm||77 mm||105 mm||733 g||300||Y||Jun 2015||999|
|2.||Pentax K-3 II||131 mm||100 mm||77 mm||800 g||720||Y||Apr 2015||1,099|
|3.||Canon 80D||139 mm||105 mm||79 mm||730 g||960||Y||Feb 2016||1,199|
|4.||Canon G9 X||98 mm||58 mm||31 mm||209 g||220||n||Oct 2015||529|
|5.||Canon G7 X||103 mm||60 mm||40 mm||304 g||210||n||Sep 2014||699|
|6.||Canon 70D||139 mm||104 mm||79 mm||755 g||920||Y||Jul 2013||1,199|
|7.||Panasonic FZ1000||137 mm||99 mm||131 mm||831 g||360||n||Jun 2014||899|
|8.||Pentax K-3 III||135 mm||104 mm||74 mm||820 g||800||Y||Mar 2021||1,999|
|9.||Pentax KP||132 mm||101 mm||76 mm||703 g||390||Y||Jan 2017||1,099|
|10.||Pentax K-S2||123 mm||91 mm||73 mm||678 g||410||Y||Feb 2015||749|
|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.||Sony RX10 III||133 mm||94 mm||127 mm||1051 g||420||Y||Mar 2016||1,499|
|14.||Sony RX100 V||102 mm||58 mm||41 mm||299 g||220||n||Oct 2016||999|
|15.||Sony RX10 II||129 mm||88 mm||102 mm||813 g||400||Y||Jun 2015||1,299|
|16.||Sony RX100 IV||102 mm||58 mm||41 mm||298 g||280||n||Jun 2015||999|
|17.||Sony RX10||129 mm||88 mm||102 mm||813 g||420||Y||Oct 2013||1,299|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or 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 G3X was launched at a lower price than the K-3 II, despite having a lens built in. 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.
The size of the sensor inside a digital camera is one of the key determinants of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Canon G3 X features an one-inch sensor and the Pentax K-3 II an APS-C sensor. The sensor area in the K-3 II is 216 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.7 and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
With 24.1MP, the K-3 II offers a higher resolution than the G3X (20MP), but the K-3 II nevertheless has larger individual pixels (pixel pitch of 3.90μm versus 2.41μm for the G3X) due to its larger sensor. It is noteworthy in this context that the two cameras were released in close succession, so that their sensors are from the same technological generation. 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.
The resolution advantage of the Pentax K-3 II implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-3 II for good quality output (200 dots per inch) amounts to 30.1 x 20 inches or 76.4 x 50.8 cm, for very good quality (250 dpi) 24.1 x 16 inches or 61.1 x 40.6 cm, and for excellent quality (300 dpi) 20.1 x 13.3 inches or 50.9 x 33.9 cm. The corresponding values for the Canon G3 X are 27.4 x 18.2 inches or 69.5 x 46.3 cm for good quality, 21.9 x 14.6 inches or 55.6 x 37.1 cm for very good quality, and 18.2 x 12.2 inches or 46.3 x 30.9 cm for excellent quality prints.
Unlike the G3X, 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 Canon PowerShot G3 X has a native sensitivity range from ISO 125 to ISO 12800, which can be extended to ISO 125-25600. The corresponding ISO settings for the Pentax K-3 II are ISO 100 to ISO 51200 (no boost).
Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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 K-3 II offers substantially better image quality than the G3X (overall score 17 points higher). The advantage is based on 2.2 bits higher color depth, 1.3 EV in additional dynamic range, and 1.1 stops in additional low light sensitivity. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
| DXO |
|1.||Canon G3 X||1-inch||20.0||5472||3648||1080/60p||21.4||12.3||521||63|
|2.||Pentax K-3 II||APS-C||24.1||6016||4000||1080/60i||23.6||13.6||1106||80|
|4.||Canon G9 X||1-inch||20.0||5472||3648||1080/60p||21.5||12.3||495||63|
|5.||Canon G7 X||1-inch||20.0||5472||3648||1080/60p||23.0||12.7||556||71|
|8.||Pentax K-3 III||APS-C||25.6||6192||4128||4K/30p||..||..||..||..|
|12.||Pentax K-5 II||APS-C||16.1||4928||3264||1080/25p||23.8||14.1||1235||82|
|13.||Sony RX10 III||1-inch||20.0||5472||3648||4K/30p||23.1||12.6||472||70|
|14.||Sony RX100 V||1-inch||20.0||5472||3648||4K/30p||22.8||12.4||586||70|
|15.||Sony RX10 II||1-inch||20.0||5472||3648||4K/30p||23.0||12.6||531||70|
|16.||Sony RX100 IV||1-inch||20.0||5472||3648||4K/30p||22.8||12.6||591||70|
Many modern cameras are not only capable of taking still images, but can also record movies. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the G3X provides a higher frame rate than the K-3 II. It can shoot video footage at 1080/60p, while the Pentax is limited to 1080/60i.
Beyond body and sensor, cameras can and do differ across a range of features. For example, the K-3 II has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the G3X relies on live view and the rear LCD for framing. That said, the G3X can be equipped with an optional viewfinder – the EVF-DC1. The following table reports on some other key feature differences and similarities of the Canon G3 X, the Pentax K-3 II, and comparable cameras.
|1.||Canon G3 X||optional||n||3.2||1620||tilting||Y||1/2000s||5.9||Y||Y|
|2.||Pentax K-3 II||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||n||Y|
|4.||Canon G9 X||none||n||3.0||1040||fixed||Y||1/2000s||6.0||Y||Y|
|5.||Canon G7 X||none||n||3.0||1040||tilting||Y||1/2000s||6.5||Y||Y|
|8.||Pentax K-3 III||optical||Y||3.2||1620||fixed||Y||1/8000s||12.0||n||Y|
|12.||Pentax K-5 II||optical||Y||3.0||921||fixed||n||1/8000s||7.0||Y||Y|
|13.||Sony RX10 III||2359||Y||3.0||1229||tilting||n||1/2000s||14.0||Y||Y|
|14.||Sony RX100 V||2359||n||3.0||1229||tilting||n||1/2000s||24.0||Y||Y|
|15.||Sony RX10 II||2359||Y||3.0||1229||tilting||n||1/3200s||14.0||Y||Y|
|16.||Sony RX100 IV||2359||n||3.0||1228||tilting||n||1/2000s||16.0||Y||Y|
One difference between the cameras concerns the presence of an on-board flash. The G3X has one, while the K-3 II does not. While the built-in flash of the G3X is not very powerful, it can at times be useful as a fill-in light.The G3X 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 K-3 II does not have a selfie-screen.
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.
Concerning the storage of imaging data, both the G3X and the K-3 II write their files to SDXC cards. The K-3 II features dual card slots, which can be very useful in case a memory card fails. In contrast, the G3X 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 Canon PowerShot G3 X and Pentax K-3 II and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|1.||Canon G3 X||Y||stereo||mono||Y||Y||mini||2.0||Y||Y||-|
|2.||Pentax K-3 II||Y||mono||mono||Y||Y||mini||3.0||-||-||-|
|4.||Canon G9 X||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|5.||Canon G7 X||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|8.||Pentax K-3 III||Y||stereo||mono||Y||Y||micro||3.2||Y||-||Y|
|12.||Pentax K-5 II||Y||stereo||mono||Y||-||mini||2.0||-||-||-|
|13.||Sony RX10 III||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|14.||Sony RX100 V||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|15.||Sony RX10 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|16.||Sony RX100 IV||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
It is notable that the G3X offers wifi support, while the K-3 II does not. Wifi can be a very convenient means to transfer image data to an off-camera location.
Studio photographers will appreciate that the Pentax K-3 II (unlike the G3X) 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 K-3 II has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.
The G3X is a recent model that features in the current product line-up of Canon. In contrast, the K-3 II has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the K-3 II was succeeded by the Pentax K-3 III. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Canon and Pentax websites.
So how do things add up? Which of the two cameras – the Canon G3 X or the Pentax K-3 II – has the upper hand? Is one clearly better than the other? A synthesis of the relative strong points of each of the models is listed below.
Arguments in favor of the Canon PowerShot G3 X:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better video: Provides higher movie framerates (1080/60p versus 1080/60i).
- More detailed LCD: Has a higher resolution rear screen (1620k vs 1037k dots).
- More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
- Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- Ready to shoot: Comes with a built-in lens, while the K-3 II requires a separate lens.
- More compact: Is smaller (123x77mm vs 131x100mm) and thus needs less room in the bag.
- Less heavy: Is lighter even though it comes with a built-in lens (unlike the K-3 II).
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
- Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
- More affordable: Was introduced at a lower price, despite coming with a built-in lens.
Reasons to prefer the Pentax K-3 II:
- More detail: Has more megapixels (24.1 vs 20MP), which boosts linear resolution by 10%.
- 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 image quality: Scores substantially higher (17 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (2.2 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (1.3 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (1.1 stops ISO advantage).
- Easier framing: Has an optical viewfinder for image composition and settings control.
- Easier setting verification: Features a control panel on top to check shooting parameters.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/2000s) to freeze action.
- Faster burst: Shoots at higher frequency (8.3 vs 5.9 flaps/sec) to capture the decisive moment.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More flexible: Makes it possible to change lenses and thus to use specialty optics.
- Longer lasting: Gets more shots (720 versus 300) out of a single battery charge.
- Easier geotagging: Features an internal GPS sensor to log localization data.
- Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
- 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.
If the count of individual advantages (bullet points above) is taken as a guide, the K-3 II is the clear winner of the contest (18 : 13 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 Canon G3 X and the Pentax K-3 II place the cameras among the top in their class? Find out in the latest Best Superzoom Camera and Best DSLR Camera listings 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 remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the G3X or the K-3 II. 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], 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.||Canon G3 X||3.5/5||+||..||4.5/5||4/5||Jun 2015||999|
|2.||Pentax K-3 II||4.5/5||..||..||5/5||5/5||Apr 2015||1,099|
|3.||Canon 80D||4/5||+ +||84/100||4.5/5||4.5/5||Feb 2016||1,199|
|4.||Canon G9 X||3.5/5||+ +||..||4.5/5||4.5/5||Oct 2015||529|
|5.||Canon G7 X||4/5||+ +||77/100||4.5/5||4.5/5||Sep 2014||699|
|6.||Canon 70D||5/5||+ +||83/100||4.5/5||5/5||Jul 2013||1,199|
|7.||Panasonic FZ1000||4/5||+ +||82/100||4.5/5||4.5/5||Jun 2014||899|
|8.||Pentax K-3 III||..||..||..||..||..||Mar 2021||1,999|
|9.||Pentax KP||4/5||..||82/100||5/5||4.5/5||Jan 2017||1,099|
|10.||Pentax K-S2||4.5/5||..||..||5/5||4.5/5||Feb 2015||749|
|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.||Sony RX10 III||5/5||+||84/100||4.5/5||4.5/5||Mar 2016||1,499|
|14.||Sony RX100 V||4.5/5||+ +||83/100||4/5||4.5/5||Oct 2016||999|
|15.||Sony RX10 II||5/5||+ +||82/100||4.5/5||4/5||Jun 2015||1,299|
|16.||Sony RX100 IV||4.5/5||+ +||85/100||4/5||4.5/5||Jun 2015||999|
|17.||Sony RX10||5/5||+||80/100||4.5/5||4.5/5||Oct 2013||1,299|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
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? In case you are interested in seeing how other cameras pair up, just make your choice using the following search menu. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.
Specifications: Canon G3 X vs Pentax K-3 II
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||Canon G3 X||Pentax K-3 II|
|Camera Type||Fixed lens compact camera||Digital single lens reflex|
|Camera Lens||24-600mm f/2.8-5.6||Pentax K mount lenses|
|Launch Date||June 2015||April 2015|
|Launch Price||USD 999||USD 1,099|
|Sensor Specs||Canon G3 X||Pentax K-3 II|
|Sensor Format||1" Sensor||APS-C Sensor|
|Sensor Size||13.2 x 8.8 mm||23.5 x 15.6 mm|
|Sensor Area||116.16 mm2||366.6 mm2|
|Sensor Diagonal||15.9 mm||28.2 mm|
|Sensor Resolution||20 Megapixels||24.1 Megapixels|
|Image Resolution||5472 x 3648 pixels||6016 x 4000 pixels|
|Pixel Pitch||2.41 μm||3.90 μm|
|Pixel Density||17.18 MP/cm2||6.56 MP/cm2|
|Moiré control||Anti-Alias filter||no AA filter|
|Movie Capability||1080/60p Video||1080/60i Video|
|ISO Setting||125 - 12,800 ISO||100 - 51,200 ISO|
|ISO Boost||125 - 25,600 ISO||no Enhancement|
|Image Processor||DIGIC 6||PRIME III|
|DXO Sensor Quality (score)||63||80|
|DXO Color Depth (bits)||21.4||23.6|
|DXO Dynamic Range (EV)||12.3||13.6|
|DXO Low Light (ISO)||521||1106|
|Screen Specs||Canon G3 X||Pentax K-3 II|
|Viewfinder Type||Viewfinder optional||Optical viewfinder|
|Viewfinder Field of View||100%|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.2inch||3.2inch|
|LCD Resolution||1620k dots||1037k dots|
|LCD Attachment||Tilting screen||Fixed screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Canon G3 X||Pentax K-3 II|
|Focus System||Contrast-detect AF||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/2000s||1/8000s|
|Continuous Shooting||5.9 shutter flaps/s||8.3 shutter flaps/s|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|Image Stabilization||Lens-based stabilization||In-body stabilization|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||SDXC cards||SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-I||UHS-I|
|Connectivity Specs||Canon G3 X||Pentax K-3 II|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 3.0|
|HDMI Port||mini HDMI||mini HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||Headphone port||Headphone port|
|Wifi Support||Wifi built-in||no Wifi|
|Near-Field Communication||NFC built-in||no NFC|
|Geotagging||no internal GPS||GPS built-in|
|Body Specs||Canon G3 X||Pentax K-3 II|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||300 shots per charge||720 shots per charge|
123 x 77 x 105 mm
(4.8 x 3.0 x 4.1 in)
131 x 100 x 77 mm
(5.2 x 3.9 x 3.0 in)
|Camera Weight||733 g (25.9 oz)||800 g (28.2 oz)|
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