Canon G1 X Mark III vs Pentax 645Z
The Canon PowerShot G1 X Mark III and the Pentax 645Z are two digital cameras that were officially introduced, respectively, in October 2017 and April 2014. The G1X Mark III is a fixed lens compact, while the 645Z is a DSLR. The cameras are based on an APS-C (G1X Mark III) and a medium format (645Z) sensor. The Canon has a resolution of 24 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 G1 X Mark III 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 physical size and weight of the Canon G1 X Mark III and the Pentax 645Z are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All width, height and depth measures 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 (103 percent) than the Canon G1 X Mark III. 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 G1X Mark III 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 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 G1 X Mark III||115 mm||78 mm||51 mm||399 g||200||Y||Oct 2017||1,299|
|2.||Pentax 645Z||156 mm||117 mm||123 mm||1550 g||650||Y||Apr 2014||8,499|
|3.||Canon 6D Mark II||144 mm||111 mm||75 mm||765 g||1200||Y||Jun 2017||1,999|
|4.||Canon 80D||139 mm||105 mm||79 mm||730 g||960||Y||Feb 2016||1,199|
|5.||Canon SX540||120 mm||82 mm||92 mm||442 g||205||n||Jan 2016||399|
|6.||Canon 5DS||152 mm||116 mm||76 mm||930 g||700||Y||Feb 2015||3,699|
|7.||Canon 5DS R||152 mm||116 mm||76 mm||930 g||700||Y||Feb 2015||3,699|
|8.||Fujifilm X100V||128 mm||75 mm||53 mm||478 g||420||Y||Feb 2020||1,399|
|9.||Fujifilm X-T3||133 mm||93 mm||59 mm||539 g||390||Y||Sep 2018||1,499|
|10.||Fujifilm X100F||127 mm||75 mm||52 mm||469 g||390||n||Jan 2017||1,299|
|11.||Hasselblad X1D||150 mm||98 mm||71 mm||725 g||..||Y||Jun 2016||8,995|
|12.||Leica SL||147 mm||104 mm||39 mm||847 g||400||Y||Oct 2015||7,450|
|13.||Nikon D7500||136 mm||104 mm||73 mm||720 g||950||Y||Apr 2017||1,299|
|14.||Pentax 645D||156 mm||117 mm||119 mm||1480 g||800||Y||Mar 2010||9,995|
|15.||Sony A6300||120 mm||67 mm||49 mm||404 g||400||Y||Feb 2016||999|
|16.||Sony A6500||120 mm||67 mm||53 mm||453 g||350||Y||Oct 2016||1,399|
|17.||Sony RX10 III||133 mm||94 mm||127 mm||1051 g||420||Y||Mar 2016||1,499|
|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 G1X Mark III was launched at a lower price than the 645Z, 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 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. 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 tend to be associated with larger, more expensive camera bodies and lenses.
Of the two cameras under consideration, the Canon G1 X Mark III features an APS-C sensor and the Pentax 645Z a medium format sensor. The sensor area in the 645Z is 333 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 0.79. The sensor in the G1X Mark III 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 G1X Mark III (24MP), but the 645Z nevertheless has larger individual pixels (pixel pitch of 5.30μm versus 3.72μm for the G1X Mark III) due to its larger sensor. However, the G1X Mark III is a much more recent model (by 3 years and 6 months) than the 645Z, 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 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 G1 X Mark III are 30 x 20 inches or 76.2 x 50.8 cm for good quality, 24 x 16 inches or 61 x 40.6 cm for very good quality, and 20 x 13.3 inches or 50.8 x 33.9 cm for excellent quality prints.
The G1X Mark III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
The Canon PowerShot G1 X Mark III has a native sensitivity range from ISO 100 to ISO 25600. The corresponding ISO settings for the Pentax 645Z are ISO 100 to ISO 204800 (no boost).
For many cameras, data on sensor performance has been reported by DXO Mark. 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 |
|1.||Canon G1 X Mark III||APS-C||24.0||6000||4000||1080/60p||..||..||..||..|
|2.||Pentax 645Z||Medium Format||51.1||8256||6192||1080/60i||26.0||14.7||4505||101|
|3.||Canon 6D Mark II||Full Frame||26.0||6240||4160||1080/60p||24.4||11.9||2862||85|
|6.||Canon 5DS||Full Frame||50.3||8688||5792||1080/30p||24.7||12.4||2381||87|
|7.||Canon 5DS R||Full Frame||50.3||8688||5792||1080/30p||24.6||12.4||2308||86|
|11.||Hasselblad X1D||Medium Format||51.3||8272||6200||1080/25p||26.2||14.8||4489||102|
|12.||Leica SL||Full Frame||24.0||6000||4000||4K/30p||25.0||13.4||1821||88|
|14.||Pentax 645D||Medium Format||39.5||7264||5440||none||24.6||12.6||1262||82|
|17.||Sony RX10 III||1-inch||20.0||5472||3648||4K/30p||23.1||12.6||472||70|
Many modern cameras cannot only take still pictures, but also record videos. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the G1X Mark III 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 variety of features. For example, the G1X Mark III has an electronic viewfinder (2360k dots), while the 645Z 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 following table reports on some other key feature differences and similarities of the Canon G1 X Mark III, the Pentax 645Z, and comparable cameras.
|1.||Canon G1 X Mark III||2360||n||3.0||1040||swivel||Y||1/2000s||9.0||Y||Y|
|3.||Canon 6D Mark II||optical||Y||3.0||1040||swivel||Y||1/4000s||6.5||n||n|
|7.||Canon 5DS R||optical||Y||3.2||1040||fixed||n||1/8000s||5.0||n||n|
|17.||Sony RX10 III||2359||Y||3.0||1229||tilting||n||1/2000s||14.0||Y||Y|
One difference between the cameras concerns the presence of an on-board flash. The G1X Mark III has one, while the 645Z does not. While the built-in flash of the G1X Mark III is not very powerful, it can at times be useful as a fill-in light.The G1X Mark III 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 Canon G1 X Mark III and the Pentax 645Z both have 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 G1X Mark III 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 G1X Mark III 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 G1 X Mark III and Pentax 645Z and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|1.||Canon G1 X Mark III||Y||stereo||mono||-||-||micro||2.0||Y||Y||Y|
|3.||Canon 6D Mark II||Y||stereo||mono||Y||-||mini||2.0||Y||Y||Y|
|7.||Canon 5DS R||Y||mono||mono||Y||-||mini||3.0||-||-||-|
|17.||Sony RX10 III||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the G1X Mark III 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 G1X Mark III) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the G1X Mark III and the 645Z are recent models that are part of the current product line-up. The 645Z replaced the earlier Pentax 645D, while the G1X Mark III followed on from the Canon G1 X Mark II. 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 G1 X Mark III or the Pentax 645Z – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.
Reasons to prefer the Canon PowerShot G1 X Mark III:
- 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 live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- More framing info: Has an electronic viewfinder that displays shooting data.
- More flexible LCD: Has a swivel screen for odd-angle shots in portrait or 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.
- Faster burst: Shoots at higher frequency (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 (115x78mm 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.
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- More affordable: Was introduced at a lower price, despite coming with a built-in lens.
- More modern: Reflects 3 years and 6 months of technical progress since the 645Z launch.
Arguments in favor of the Pentax 645Z:
- More detail: Has more megapixels (51.1 vs 24MP), which boosts linear resolution by 43%.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- Better sound: Can connect to an external microphone for higher quality sound recording.
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- Easier setting verification: Features a control panel on top to check shooting parameters.
- Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
- Faster shutter: Has higher mechanical shutter speed (1/4000s vs 1/2000s) to freeze action.
- More flexible: Makes it possible to change lenses and thus to use specialty optics.
- Longer lasting: Gets more shots (650 versus 200) 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 around for much longer (launched in April 2014).
If the count of relative strengths (bullet points above) is taken as a measure, the G1X Mark III is the clear winner of the match-up (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 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 G1 X Mark III and the Pentax 645Z place the cameras among the top in their class? Find out in the latest Best Travel-Zoom Camera and Best DSLR Camera listings 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 says little about, for example, the shooting experience and imaging performance of the G1X Mark III and the 645Z 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 why expert reviews are important. 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 G1 X Mark III||5/5||+||79/100||4.5/5||4.5/5||Oct 2017||1,299|
|2.||Pentax 645Z||5/5||..||..||4.5/5||5/5||Apr 2014||8,499|
|3.||Canon 6D Mark II||4/5||+||80/100||4.5/5||4/5||Jun 2017||1,999|
|4.||Canon 80D||4/5||+ +||84/100||4.5/5||4.5/5||Feb 2016||1,199|
|5.||Canon SX540||..||..||..||..||..||Jan 2016||399|
|6.||Canon 5DS||..||+||83/100||4.5/5||4.5/5||Feb 2015||3,699|
|7.||Canon 5DS R||5/5||+||83/100||5/5||4.5/5||Feb 2015||3,699|
|8.||Fujifilm X100V||5/5||+ +||86/100||5/5||4.5/5||Feb 2020||1,399|
|9.||Fujifilm X-T3||5/5||+ +||88/100||5/5||5/5||Sep 2018||1,499|
|10.||Fujifilm X100F||5/5||+||83/100||4.5/5||4.5/5||Jan 2017||1,299|
|11.||Hasselblad X1D||..||o||81/100||..||4/5||Jun 2016||8,995|
|12.||Leica SL||4/5||..||84/100||4.5/5||4/5||Oct 2015||7,450|
|13.||Nikon D7500||4.5/5||+ +||86/100||5/5||4.5/5||Apr 2017||1,299|
|14.||Pentax 645D||5/5||..||..||..||..||Mar 2010||9,995|
|15.||Sony A6300||4.5/5||+||85/100||5/5||5/5||Feb 2016||999|
|16.||Sony A6500||5/5||+ +||85/100||4.5/5||4.5/5||Oct 2016||1,399|
|17.||Sony RX10 III||5/5||+||84/100||4.5/5||4.5/5||Mar 2016||1,499|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The above review scores should be interpreted with care, 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 comparisons of ratings among very different cameras or across long time periods have little meaning. It should also be noted that some of the review sites have over time altered the way they render their verdicts.
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 make a corresponding selection in the search boxes below. 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 G1 X Mark III 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 G1 X Mark III||Pentax 645Z|
|Camera Type||Fixed lens compact camera||Digital single lens reflex|
|Camera Lens||24-72mm f/2.8-5.6||Pentax 645 mount lenses|
|Launch Date||October 2017||April 2014|
|Launch Price||USD 1,299||USD 8,499|
|Sensor Specs||Canon G1 X Mark III||Pentax 645Z|
|Sensor Format||APS-C Sensor||Medium Format Sensor|
|Sensor Size||22.3 x 14.9 mm||43.8 x 32.8 mm|
|Sensor Area||332.27 mm2||1436.64 mm2|
|Sensor Diagonal||26.8 mm||54.7 mm|
|Sensor Resolution||24 Megapixels||51.1 Megapixels|
|Image Resolution||6000 x 4000 pixels||8256 x 6192 pixels|
|Pixel Pitch||3.72 μm||5.30 μm|
|Pixel Density||7.22 MP/cm2||3.56 MP/cm2|
|Moiré control||Anti-Alias filter||no AA filter|
|Movie Capability||1080/60p Video||1080/60i Video|
|ISO Setting||100 - 25,600 ISO||100 - 204,800 ISO|
|Image Processor||DIGIC 7||PRIME III|
|DXO Sensor Quality (score)||..||101|
|DXO Color Depth (bits)||..||26.0|
|DXO Dynamic Range (EV)||..||14.7|
|DXO Low Light (ISO)||..||4505|
|Screen Specs||Canon G1 X Mark III||Pentax 645Z|
|Viewfinder Type||Electronic viewfinder||Optical viewfinder|
|Viewfinder Field of View||100%||98%|
|Viewfinder Resolution||2360k dots|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.2inch|
|LCD Resolution||1040k dots||1037k dots|
|LCD Attachment||Swivel screen||Tilting screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Canon G1 X Mark III||Pentax 645Z|
|Focus System||On-Sensor Phase-detect||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/2000s||1/4000s|
|Continuous Shooting||9 shutter flaps/s||3 shutter flaps/s|
|Time-Lapse Photography||Intervalometer built-in||Intervalometer built-in|
|Fill Flash||Built-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 G1 X Mark III||Pentax 645Z|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 3.0|
|HDMI Port||micro HDMI||mini HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Wifi Support||Wifi built-in||no Wifi|
|Near-Field Communication||NFC built-in||no NFC|
|Bluetooth Support||Bluetooth built-in||no Bluetooth|
|Body Specs||Canon G1 X Mark III||Pentax 645Z|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||200 shots per charge||650 shots per charge|
115 x 78 x 51 mm
(4.5 x 3.1 x 2.0 in)
156 x 117 x 123 mm
(6.1 x 4.6 x 4.8 in)
|Camera Weight||399 g (14.1 oz)||1550 g (54.7 oz)|
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