Canon G7 X vs Pentax 645D
The Canon PowerShot G7 X and the Pentax 645D are two digital cameras that were revealed to the public, respectively, in September 2014 and March 2010. The G7X is a fixed lens compact, while the 645D is a DSLR. The cameras are based on an one-inch (G7X) and a medium format (645D) sensor. The Canon has a resolution of 20 megapixels, whereas the Pentax provides 39.5 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 G7 X and the Pentax 645D? 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 G7 X and the Pentax 645D is provided 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 size 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 645D is considerably larger (195 percent) than the Canon G7 X. It is noteworthy in this context that the 645D is splash and dust-proof, while the G7X does not feature any corresponding weather-sealing.
The above size and weight comparisons are to some extent incomplete and possibly misleading, as the G7X has a lens built in, whereas the 645D 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 G7 X||103 mm||60 mm||40 mm||304 g||210||n||Sep 2014||699|
|2.||Pentax 645D||156 mm||117 mm||119 mm||1480 g||800||Y||Mar 2010||9,995|
|3.||Canon G7 X Mark III||105 mm||61 mm||41 mm||304 g||235||n||Jul 2019||749|
|4.||Canon G7 X Mark II||106 mm||61 mm||42 mm||319 g||265||n||Feb 2016||699|
|5.||Canon G5 X||112 mm||76 mm||44 mm||353 g||210||n||Oct 2015||799|
|6.||Canon G9 X||98 mm||58 mm||31 mm||209 g||220||n||Oct 2015||529|
|7.||Canon M3||111 mm||68 mm||44 mm||366 g||250||n||Feb 2015||679|
|8.||Canon M10||108 mm||67 mm||35 mm||301 g||255||n||Oct 2015||499|
|9.||Canon T6i||132 mm||101 mm||78 mm||555 g||440||n||Feb 2015||749|
|10.||Canon 1D X||158 mm||168 mm||83 mm||1551 g||1120||Y||Oct 2011||6,799|
|11.||Canon 1D Mark IV||156 mm||157 mm||80 mm||1230 g||1500||Y||Oct 2009||4,999|
|12.||Leica S Typ 006||160 mm||120 mm||80 mm||1260 g||..||Y||Sep 2012||21,950|
|13.||Nikon D3S||160 mm||157 mm||88 mm||1240 g||4200||Y||Oct 2009||5,199|
|14.||Pentax 645Z||156 mm||117 mm||123 mm||1550 g||650||Y||Apr 2014||8,499|
|15.||Sony RX100 IV||102 mm||58 mm||41 mm||298 g||280||n||Jun 2015||999|
|16.||Sony RX100 III||102 mm||58 mm||41 mm||290 g||320||n||May 2014||799|
|17.||Sony RX100 II||102 mm||58 mm||38 mm||281 g||350||n||Jun 2013||749|
|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 G7X was launched at a lower price than the 645D, 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.
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 Canon G7 X features an one-inch sensor and the Pentax 645D a medium format sensor. The sensor area in the 645D is 1152 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 G7X has a native 3:2 aspect ratio, while the one in the 645D offers a 4:3 aspect.
With 39.5MP, the 645D offers a higher resolution than the G7X (20MP), but the 645D nevertheless has larger individual pixels (pixel pitch of 6.06μm versus 2.41μm for the G7X) due to its larger sensor. However, the G7X is a much more recent model (by 4 years and 6 months) than the 645D, 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 645D has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Pentax 645D implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the 645D for good quality output (200 dots per inch) amounts to 36.3 x 27.2 inches or 92.3 x 69.1 cm, for very good quality (250 dpi) 29.1 x 21.8 inches or 73.8 x 55.3 cm, and for excellent quality (300 dpi) 24.2 x 18.1 inches or 61.5 x 46.1 cm. The corresponding values for the Canon G7 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 G7 X has a native sensitivity range from ISO 125 to ISO 12800. The corresponding ISO settings for the Pentax 645D are ISO 100 to ISO 1600 (no boost).
For many cameras, data on sensor performance has been reported by DXO Mark. 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 645D offers substantially better image quality than the G7X (overall score 11 points higher). The advantage is based on 1.6 bits higher color depth, 0.1 EV of lower dynamic range, and 1.2 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 G7 X||1-inch||20.0||5472||3648||1080/60p||23.0||12.7||556||71|
|2.||Pentax 645D||Medium Format||39.5||7264||5440||none||24.6||12.6||1262||82|
|3.||Canon G7 X Mark III||1-inch||20.0||5472||3648||4K/30p||..||..||..||..|
|4.||Canon G7 X Mark II||1-inch||20.0||5472||3648||1080/60p||..||..||..||..|
|5.||Canon G5 X||1-inch||20.0||5472||3648||1080/60p||..||..||..||..|
|6.||Canon G9 X||1-inch||20.0||5472||3648||1080/60p||21.5||12.3||495||63|
|10.||Canon 1D X||Full Frame||17.9||5184||3456||1080/30p||23.8||11.8||2786||82|
|11.||Canon 1D Mark IV||APS-H||16.0||4896||3264||1080/30p||22.8||12.0||1320||74|
|12.||Leica S Typ 006||Medium Format||37.5||7500||5000||none||23.9||12.2||824||76|
|13.||Nikon D3S||Full Frame||12.1||4256||2832||720/24p||23.5||12.0||3253||82|
|14.||Pentax 645Z||Medium Format||51.1||8256||6192||1080/60i||26.0||14.7||4505||101|
|15.||Sony RX100 IV||1-inch||20.0||5472||3648||4K/30p||22.8||12.6||591||70|
|16.||Sony RX100 III||1-inch||20.0||5472||3648||1080/60p||22.4||12.3||495||67|
|17.||Sony RX100 II||1-inch||20.0||5472||3648||1080/60p||22.5||12.4||483||67|
Many modern cameras are not only capable of taking still images, but can also record movies. The G7X indeed provides movie recording capabilities, while the 645D does not. The highest resolution format that the G7X can use is 1080/60p.
Apart from body and sensor, cameras can and do differ across a range of features. For example, the 645D has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the G7X relies on live view and the rear LCD for framing. The table below summarizes some of the other core capabilities of the Canon G7 X and Pentax 645D in connection with corresponding information for a sample of similar cameras.
|1.||Canon G7 X||none||n||3.0||1040||tilting||Y||1/2000s||6.5||Y||Y|
|3.||Canon G7 X Mark III||none||n||3.0||1040||tilting||Y||1/2000s||30||Y||Y|
|4.||Canon G7 X Mark II||none||n||3.0||1040||tilting||Y||1/2000s||8.0||Y||Y|
|5.||Canon G5 X||2360||n||3.0||1040||swivel||Y||1/2000s||5.9||Y||Y|
|6.||Canon G9 X||none||n||3.0||1040||fixed||Y||1/2000s||6.0||Y||Y|
|10.||Canon 1D X||optical||Y||3.2||1040||fixed||n||1/8000s||14.0||n||n|
|11.||Canon 1D Mark IV||optical||Y||3.0||920||fixed||n||1/8000s||10.0||n||n|
|12.||Leica S Typ 006||optical||Y||3.0||922||fixed||n||1/4000s||1.5||n||n|
|15.||Sony RX100 IV||2359||n||3.0||1228||tilting||n||1/2000s||16.0||Y||Y|
|16.||Sony RX100 III||1440||n||3.0||1229||tilting||n||1/2000s||10.0||Y||Y|
|17.||Sony RX100 II||optional||n||3.0||1229||tilting||n||1/2000s||10.0||Y||Y|
One difference between the cameras concerns the presence of an on-board flash. The G7X has one, while the 645D does not. While the built-in flash of the G7X is not very powerful, it can at times be useful as a fill-in light.The G7X 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 645D does not have a selfie-screen.
The Canon G7 X and the Pentax 645D 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 G7X and the 645D write their files to SDXC cards. The 645D features dual card slots, which can be very useful in case a memory card fails. In contrast, the G7X only has one slot. The G7X supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the 645D 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 Canon PowerShot G7 X and Pentax 645D and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|1.||Canon G7 X||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|3.||Canon G7 X Mark III||-||stereo||mono||Y||-||micro||3.1||Y||-||Y|
|4.||Canon G7 X Mark II||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|5.||Canon G5 X||Y||stereo||mono||-||-||mini||2.0||Y||Y||-|
|6.||Canon G9 X||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|10.||Canon 1D X||Y||mono||-||Y||-||mini||2.0||-||-||-|
|11.||Canon 1D Mark IV||Y||stereo||-||Y||-||mini||2.0||-||-||-|
|12.||Leica S Typ 006||Y||-||-||-||-||mini||2.0||-||-||-|
|15.||Sony RX100 IV||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|16.||Sony RX100 III||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|17.||Sony RX100 II||Y||stereo||mono||-||-||micro||2.0||Y||Y||-|
It is notable that the G7X offers wifi support, while the 645D 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 645D (unlike the G7X) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the G7X and the 645D have been discontinued, but can regularly be found used on eBay. The 645D was replaced by the Pentax 645Z, while the G7X was followed by the Canon G7 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 what is the bottom line? Is there a clear favorite between the Canon G7 X and the Pentax 645D? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.
Reasons to prefer the Canon PowerShot G7 X:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Broader imaging potential: Can record not only still images but also 1080/60p movies.
- More detailed LCD: Has a higher resolution rear screen (1040k vs 921k 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.
- Faster burst: Shoots at higher frequency (6.5 vs 1.1 flaps/sec) to capture the decisive moment.
- Ready to shoot: Comes with a built-in lens, while the 645D requires a separate lens.
- More compact: Is smaller (103x60mm 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 645D).
- 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.
- Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
- More affordable: Was introduced at a lower price, despite coming with a built-in lens.
- More modern: Reflects 4 years and 6 months of technical progress since the 645D launch.
Advantages of the Pentax 645D:
- More detail: Has more megapixels (39.5 vs 20MP), which boosts linear resolution by 38%.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- Better image quality: Scores substantially higher (11 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (1.6 bits more color depth).
- Better low-light sensitivity: Can shoot in dim conditions (1.2 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.
- More flexible: Makes it possible to change lenses and thus to use specialty optics.
- Longer lasting: Gets more shots (800 versus 210) out of a single battery charge.
- Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
- Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
- 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 March 2010).
If the count of relative strengths (bullet points above) is taken as a measure, the G7X emerges as the winner of the contest (17 : 15 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 G7 X and the Pentax 645D 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 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 G7X and the 645D 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 hands-on reviews by experts 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 G7 X||4/5||+ +||77/100||4.5/5||4.5/5||Sep 2014||699|
|2.||Pentax 645D||5/5||..||..||..||..||Mar 2010||9,995|
|3.||Canon G7 X Mark III||..||+ +||81/100||4/5||..||Jul 2019||749|
|4.||Canon G7 X Mark II||4.5/5||+ +||81/100||4.5/5||4.5/5||Feb 2016||699|
|5.||Canon G5 X||5/5||+ +||78/100||4.5/5||4.5/5||Oct 2015||799|
|6.||Canon G9 X||3.5/5||+ +||..||4.5/5||4.5/5||Oct 2015||529|
|7.||Canon M3||4/5||o||75/100||4.5/5||4/5||Feb 2015||679|
|8.||Canon M10||..||..||..||..||4/5||Oct 2015||499|
|9.||Canon T6i||5/5||..||75/100||4.5/5||4.5/5||Feb 2015||749|
|10.||Canon 1D X||5/5||..||..||4.5/5||4.5/5||Oct 2011||6,799|
|11.||Canon 1D Mark IV||5/5||..||89/100||..||..||Oct 2009||4,999|
|12.||Leica S Typ 006||..||..||..||..||..||Sep 2012||21,950|
|13.||Nikon D3S||5/5||..||89/100||4.5/5||5/5||Oct 2009||5,199|
|14.||Pentax 645Z||5/5||..||..||4.5/5||5/5||Apr 2014||8,499|
|15.||Sony RX100 IV||4.5/5||+ +||85/100||4/5||4.5/5||Jun 2015||999|
|16.||Sony RX100 III||5/5||+ +||82/100||4.5/5||5/5||May 2014||799|
|17.||Sony RX100 II||5/5||+ +||79/100||4.5/5||4.5/5||Jun 2013||749|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
Care should be taken when interpreting the review scores above, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. 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, 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 G7 X vs Pentax 645D
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 G7 X||Pentax 645D|
|Camera Type||Fixed lens compact camera||Digital single lens reflex|
|Camera Lens||24-100mm f/1.8-2.8||Pentax 645 mount lenses|
|Launch Date||September 2014||March 2010|
|Launch Price||USD 699||USD 9,995|
|Sensor Specs||Canon G7 X||Pentax 645D|
|Sensor Format||1" Sensor||Medium Format Sensor|
|Sensor Size||13.2 x 8.8 mm||44.0 x 33.0 mm|
|Sensor Area||116.16 mm2||1452 mm2|
|Sensor Diagonal||15.9 mm||55 mm|
|Sensor Resolution||20 Megapixels||39.5 Megapixels|
|Image Resolution||5472 x 3648 pixels||7264 x 5440 pixels|
|Pixel Pitch||2.41 μm||6.06 μm|
|Pixel Density||17.18 MP/cm2||2.72 MP/cm2|
|Moiré control||Anti-Alias filter||no AA filter|
|Movie Capability||1080/60p Video||no Video|
|ISO Setting||125 - 12,800 ISO||100 - 1,600 ISO|
|Image Processor||DIGIC 6||PRIME II|
|DXO Sensor Quality (score)||71||82|
|DXO Color Depth (bits)||23.0||24.6|
|DXO Dynamic Range (EV)||12.7||12.6|
|DXO Low Light (ISO)||556||1262|
|Screen Specs||Canon G7 X||Pentax 645D|
|Viewfinder Type||no viewfinder||Optical viewfinder|
|Viewfinder Field of View||98%|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1040k dots||921k dots|
|LCD Attachment||Tilting screen||Fixed screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Canon G7 X||Pentax 645D|
|Focus System||Contrast-detect AF||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||no Peaking Feature|
|Continuous Shooting||6.5 shutter flaps/s||1.1 shutter flaps/s|
|Time-Lapse Photography||Intervalometer built-in||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||no|
|Connectivity Specs||Canon G7 X||Pentax 645D|
|External Flash||no Hotshoe||Hotshoe|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||micro HDMI||no HDMI|
|Wifi Support||Wifi built-in||no Wifi|
|Near-Field Communication||NFC built-in||no NFC|
|Body Specs||Canon G7 X||Pentax 645D|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||210 shots per charge||800 shots per charge|
103 x 60 x 40 mm
(4.1 x 2.4 x 1.6 in)
156 x 117 x 119 mm
(6.1 x 4.6 x 4.7 in)
|Camera Weight||304 g (10.7 oz)||1480 g (52.2 oz)|
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