Canon G3 X vs Pentax 645Z
The Canon PowerShot G3 X and the Pentax 645Z are two digital cameras that were officially introduced, respectively, in June 2015 and April 2014. The G3X is a fixed lens compact, while the 645Z is a DSLR. The cameras are based on an one-inch (G3X) and a medium format (645Z) sensor. The Canon has a resolution of 20 megapixels, whereas the Pentax provides 51.1 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 645Z? 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 Canon G3 X and the Pentax 645Z. 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.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax 645Z is considerably larger (93 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 645Z 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 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.
|1.||Canon G3 X||123 mm||77 mm||105 mm||733 g||300||Y||Jun 2015||999|
|2.||Pentax 645Z||156 mm||117 mm||123 mm||1550 g||650||Y||Apr 2014||8,499|
|3.||Canon 80D||139 mm||105 mm||79 mm||730 g||960||Y||Feb 2016||1,199|
|4.||Canon 5DS||152 mm||116 mm||76 mm||930 g||700||Y||Feb 2015||3,699|
|5.||Canon 5DS R||152 mm||116 mm||76 mm||930 g||700||Y||Feb 2015||3,699|
|6.||Canon G9 X||98 mm||58 mm||31 mm||209 g||220||n||Oct 2015||529|
|7.||Canon 7D II||149 mm||112 mm||78 mm||910 g||670||Y||Sep 2014||1,799|
|8.||Canon 70D||139 mm||104 mm||79 mm||755 g||920||Y||Jul 2013||1,199|
|9.||Hasselblad X1D||150 mm||98 mm||71 mm||725 g||..||Y||Jun 2016||8,995|
|10.||Leica SL||147 mm||104 mm||39 mm||847 g||400||Y||Oct 2015||7,450|
|11.||Nikon D7200||136 mm||107 mm||76 mm||765 g||1110||Y||Mar 2015||1,199|
|12.||Panasonic FZ1000||137 mm||99 mm||131 mm||831 g||360||n||Jun 2014||899|
|13.||Pentax 645D||156 mm||117 mm||119 mm||1480 g||800||Y||Mar 2010||9,995|
|14.||Sony RX10 III||133 mm||94 mm||127 mm||1051 g||420||Y||Mar 2016||1,499|
|15.||Sony RX100 V||102 mm||58 mm||41 mm||299 g||220||n||Oct 2016||999|
|16.||Sony RX10 II||129 mm||88 mm||102 mm||813 g||400||Y||Jun 2015||1,299|
|17.||Sony RX100 IV||102 mm||58 mm||41 mm||298 g||280||n||Jun 2015||999|
|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 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 G3X was launched at a lower price than the 645Z, despite having a lens built in. 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.
The imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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 associated with larger, more expensive camera bodies and lenses.
Of the two cameras under consideration, the Canon G3 X features an one-inch sensor and the Pentax 645Z a medium format sensor. The sensor area in the 645Z is 1139 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.7 and 0.79. The sensor in the G3X has a native 3:2 aspect ratio, while the one in the 645Z offers a 4:3 aspect.
With 51.1MP, the 645Z offers a higher resolution than the G3X (20MP), but the 645Z nevertheless has larger individual pixels (pixel pitch of 5.30μm versus 2.41μm for the G3X) due to its larger sensor. However, the G3X is a somewhat more recent model (by 1 year and 2 months) than the 645Z, and its sensor might 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 645Z has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Pentax 645Z implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the 645Z for good quality output (200 dots per inch) amounts to 41.3 x 31 inches or 104.9 x 78.6 cm, for very good quality (250 dpi) 33 x 24.8 inches or 83.9 x 62.9 cm, and for excellent quality (300 dpi) 27.5 x 20.6 inches or 69.9 x 52.4 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.
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 645Z are ISO 100 to ISO 204800 (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"). Of the two cameras under consideration, the 645Z offers substantially better image quality than the G3X (overall score 38 points higher). The advantage is based on 4.6 bits higher color depth, 2.4 EV in additional dynamic range, and 3.1 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.
| DXO |
|1.||Canon G3 X||1-inch||20.0||5472||3648||1080/60p||21.4||12.3||521||63|
|2.||Pentax 645Z||Medium Format||51.1||8256||6192||1080/60i||26.0||14.7||4505||101|
|4.||Canon 5DS||Full Frame||50.3||8688||5792||1080/30p||24.7||12.4||2381||87|
|5.||Canon 5DS R||Full Frame||50.3||8688||5792||1080/30p||24.6||12.4||2308||86|
|6.||Canon G9 X||1-inch||20.0||5472||3648||1080/60p||21.5||12.3||495||63|
|7.||Canon 7D II||APS-C||20.0||5472||3648||1080/60p||22.4||11.8||1082||70|
|9.||Hasselblad X1D||Medium Format||51.3||8272||6200||1080/25p||26.2||14.8||4489||102|
|10.||Leica SL||Full Frame||24.0||6000||4000||4K/30p||25.0||13.4||1821||88|
|13.||Pentax 645D||Medium Format||39.5||7264||5440||none||24.6||12.6||1262||82|
|14.||Sony RX10 III||1-inch||20.0||5472||3648||4K/30p||23.1||12.6||472||70|
|15.||Sony RX100 V||1-inch||20.0||5472||3648||4K/30p||22.8||12.4||586||70|
|16.||Sony RX10 II||1-inch||20.0||5472||3648||4K/30p||23.0||12.6||531||70|
|17.||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. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the G3X provides a higher frame rate than the 645Z. It can shoot video footage at 1080/60p, while the Pentax is limited to 1080/60i.
Apart from body and sensor, cameras can and do differ across a range of features. For example, the 645Z 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 645Z, and comparable cameras.
|1.||Canon G3 X||optional||n||3.2||1620||tilting||Y||1/2000s||5.9||Y||Y|
|5.||Canon 5DS R||optical||Y||3.2||1040||fixed||n||1/8000s||5.0||n||n|
|6.||Canon G9 X||none||n||3.0||1040||fixed||Y||1/2000s||6.0||Y||Y|
|7.||Canon 7D II||optical||Y||3.0||1040||fixed||n||1/8000s||10.0||Y||n|
|14.||Sony RX10 III||2359||Y||3.0||1229||tilting||n||1/2000s||14.0||Y||Y|
|15.||Sony RX100 V||2359||n||3.0||1229||tilting||n||1/2000s||24.0||Y||Y|
|16.||Sony RX10 II||2359||Y||3.0||1229||tilting||n||1/3200s||14.0||Y||Y|
|17.||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 645Z 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 645Z does not have a selfie-screen.
The Pentax 645Z 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 645Z write their files to SDXC cards. The 645Z 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 645Z 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||-|
|5.||Canon 5DS R||Y||mono||mono||Y||-||mini||3.0||-||-||-|
|6.||Canon G9 X||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|7.||Canon 7D II||Y||stereo||mono||Y||Y||mini||3.0||-||-||-|
|14.||Sony RX10 III||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|15.||Sony RX100 V||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|16.||Sony RX10 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|17.||Sony RX100 IV||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
It is notable that the G3X offers wifi support, while the 645Z 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 645Z (unlike the G3X) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the G3X and the 645Z are recent models that are part of the current product line-up. The 645Z replaced the earlier Pentax 645D, while the G3X does not have a direct predecessor. 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? Is the Canon G3 X better than the Pentax 645Z or vice versa? The listing below highlights the relative strengths of the two models.
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).
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- More detailed LCD: Has a higher resolution rear screen (1620k vs 1037k dots).
- 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.
- Faster burst: Shoots at higher frequency (5.9 vs 3 flaps/sec) to capture the decisive moment.
- Ready to shoot: Comes with a built-in lens, while the 645Z requires a separate lens.
- More compact: Is smaller (123x77mm vs 156x117mm) and thus needs less room in the bag.
- Less heavy: Is lighter even though it comes with a built-in lens (unlike the 645Z).
- Sharper images: Has hand-shake reducing image stabilization built-in.
- 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.
- More modern: Is somewhat more recent (announced 1 year and 2 months after the 645Z).
Reasons to prefer the Pentax 645Z:
- More detail: Has more megapixels (51.1 vs 20MP), which boosts linear resolution by 57%.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- Better image quality: Scores substantially higher (38 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (4.6 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (2.4 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (3.1 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 (1/4000s vs 1/2000s) to freeze action.
- 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 (650 versus 300) out of a single battery charge.
- 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.
- More heavily discounted: Has been on the market for longer (launched in April 2014).
If the count of individual advantages (bullet points above) is taken as a guide, the match-up finishes in a tie (16 points each). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features before making a decision on a new camera. 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 Canon G3 X and the Pentax 645Z 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 comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it says little about, for example, the shooting experience and imaging performance of the G3X and the 645Z 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 following table reports the overall ratings of the cameras as published by some of the major 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 645Z||5/5||..||..||4.5/5||5/5||Apr 2014||8,499|
|3.||Canon 80D||4/5||+ +||84/100||4.5/5||4.5/5||Feb 2016||1,199|
|4.||Canon 5DS||..||+||83/100||4.5/5||4.5/5||Feb 2015||3,699|
|5.||Canon 5DS R||5/5||+||83/100||5/5||4.5/5||Feb 2015||3,699|
|6.||Canon G9 X||3.5/5||+ +||..||4.5/5||4.5/5||Oct 2015||529|
|7.||Canon 7D II||4.5/5||+||84/100||4/5||4.5/5||Sep 2014||1,799|
|8.||Canon 70D||5/5||+ +||83/100||4.5/5||5/5||Jul 2013||1,199|
|9.||Hasselblad X1D||..||o||81/100||..||4/5||Jun 2016||8,995|
|10.||Leica SL||4/5||..||84/100||4.5/5||4/5||Oct 2015||7,450|
|11.||Nikon D7200||4/5||+ +||84/100||4.5/5||4.5/5||Mar 2015||1,199|
|12.||Panasonic FZ1000||4/5||+ +||82/100||4.5/5||4.5/5||Jun 2014||899|
|13.||Pentax 645D||5/5||..||..||..||..||Mar 2010||9,995|
|14.||Sony RX10 III||5/5||+||84/100||4.5/5||4.5/5||Mar 2016||1,499|
|15.||Sony RX100 V||4.5/5||+ +||83/100||4/5||4.5/5||Oct 2016||999|
|16.||Sony RX10 II||5/5||+ +||82/100||4.5/5||4/5||Jun 2015||1,299|
|17.||Sony RX100 IV||4.5/5||+ +||85/100||4/5||4.5/5||Jun 2015||999|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The above review scores should be interpreted with care, 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 rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, please note that some of the review sites have changed their methodology and reporting over time.
Other camera comparisons
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Specifications: Canon G3 X vs Pentax 645Z
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 645Z|
|Camera Type||Fixed lens compact camera||Digital single lens reflex|
|Camera Lens||24-600mm f/2.8-5.6||Pentax 645 mount lenses|
|Launch Date||June 2015||April 2014|
|Launch Price||USD 999||USD 8,499|
|Sensor Specs||Canon G3 X||Pentax 645Z|
|Sensor Format||1" Sensor||Medium Format Sensor|
|Sensor Size||13.2 x 8.8 mm||43.8 x 32.8 mm|
|Sensor Area||116.16 mm2||1436.64 mm2|
|Sensor Diagonal||15.9 mm||54.7 mm|
|Sensor Resolution||20 Megapixels||51.1 Megapixels|
|Image Resolution||5472 x 3648 pixels||8256 x 6192 pixels|
|Pixel Pitch||2.41 μm||5.30 μm|
|Pixel Density||17.18 MP/cm2||3.56 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 - 204,800 ISO|
|ISO Boost||125 - 25,600 ISO||no Enhancement|
|Image Processor||DIGIC 6||PRIME III|
|DXO Sensor Quality (score)||63||101|
|DXO Color Depth (bits)||21.4||26.0|
|DXO Dynamic Range (EV)||12.3||14.7|
|DXO Low Light (ISO)||521||4505|
|Screen Specs||Canon G3 X||Pentax 645Z|
|Viewfinder Type||Viewfinder optional||Optical viewfinder|
|Viewfinder Field of View||98%|
|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||Tilting screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Canon G3 X||Pentax 645Z|
|Focus System||Contrast-detect AF||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/2000s||1/4000s|
|Continuous Shooting||5.9 shutter flaps/s||3 shutter flaps/s|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|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 645Z|
|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||no Headphone port|
|Wifi Support||Wifi built-in||no Wifi|
|Near-Field Communication||NFC built-in||no NFC|
|Body Specs||Canon G3 X||Pentax 645Z|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||300 shots per charge||650 shots per charge|
123 x 77 x 105 mm
(4.8 x 3.0 x 4.1 in)
156 x 117 x 123 mm
(6.1 x 4.6 x 4.8 in)
|Camera Weight||733 g (25.9 oz)||1550 g (54.7 oz)|
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