Canon G7 X vs Pentax 645Z
The Canon PowerShot G7 X and the Pentax 645Z are two digital cameras that were revealed to the public, respectively, in September 2014 and April 2014. The G7X is a fixed lens compact, while the 645Z is a DSLR. The cameras are based on an one-inch (G7X) 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 G7 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 G7 X and the Pentax 645Z. 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 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 (195 percent) than the Canon G7 X. It is noteworthy in this context that the 645Z 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 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. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.
|1.||Canon G7 X||103 mm||60 mm||40 mm||304 g||210||n||Sep 2014||699|
|2.||Pentax 645Z||156 mm||117 mm||123 mm||1550 g||650||Y||Apr 2014||8,499|
|3.||Canon G7 X Mark II||106 mm||61 mm||42 mm||319 g||265||n||Feb 2016||699|
|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 750D||132 mm||101 mm||78 mm||555 g||440||n||Feb 2015||749|
|7.||Canon G5 X||112 mm||76 mm||44 mm||353 g||210||n||Oct 2015||799|
|8.||Canon G9 X||98 mm||58 mm||31 mm||209 g||220||n||Oct 2015||529|
|9.||Canon M3||111 mm||68 mm||44 mm||366 g||250||n||Feb 2015||679|
|10.||Canon M10||108 mm||67 mm||35 mm||301 g||255||n||Oct 2015||499|
|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.||Pentax 645D||156 mm||117 mm||119 mm||1480 g||800||Y||Mar 2010||9,995|
|14.||Sony RX100 IV||102 mm||58 mm||41 mm||298 g||280||n||Jun 2015||999|
|15.||Sony A6000||120 mm||67 mm||45 mm||344 g||360||n||Feb 2014||599|
|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 naturally be influenced heavily by the price. The manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The G7X 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. 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 more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Canon G7 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 G7X 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 G7X (20MP), but the 645Z nevertheless has larger individual pixels (pixel pitch of 5.30μm versus 2.41μm for the G7X) due to its larger sensor. However, the G7X is a somewhat more recent model (by 5 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 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 645Z are ISO 100 to ISO 204800 (no boost).
Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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 645Z offers substantially better image quality than the G7X (overall score 30 points higher). The advantage is based on 3 bits higher color depth, 2 EV in additional dynamic range, and 3 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 G7 X||1-inch||20.0||5472||3648||1080/60p||23.0||12.7||556||71|
|2.||Pentax 645Z||Medium Format||51.1||8256||6192||1080/60i||26.0||14.7||4505||101|
|3.||Canon G7 X Mark II||1-inch||20.0||5472||3648||1080/60p||..||..||..||..|
|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|
|7.||Canon G5 X||1-inch||20.0||5472||3648||1080/60p||..||..||..||..|
|8.||Canon G9 X||1-inch||20.0||5472||3648||1080/60p||21.5||12.3||495||63|
|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|
|13.||Pentax 645D||Medium Format||39.5||7264||5440||none||24.6||12.6||1262||82|
|14.||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 two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the G7X 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 G7X relies on live view and the rear LCD for framing. The adjacent table lists some of the other core features of the Canon G7 X and Pentax 645Z along with similar information for a selection of comparators.
|1.||Canon G7 X||none||n||3.0||1040||tilting||Y||1/2000s||6.5||Y||Y|
|3.||Canon G7 X Mark II||none||n||3.0||1040||tilting||Y||1/2000s||8.0||Y||Y|
|5.||Canon 5DS R||optical||Y||3.2||1040||fixed||n||1/8000s||5.0||n||n|
|7.||Canon G5 X||2360||n||3.0||1040||swivel||Y||1/2000s||5.9||Y||Y|
|8.||Canon G9 X||none||n||3.0||1040||fixed||Y||1/2000s||6.0||Y||Y|
|14.||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 645Z 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 645Z does not have a selfie-screen.
The Canon G7 X 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 G7X 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 G7X 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 G7 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 G7 X||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|3.||Canon G7 X Mark II||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|5.||Canon 5DS R||Y||mono||mono||Y||-||mini||3.0||-||-||-|
|7.||Canon G5 X||Y||stereo||mono||-||-||mini||2.0||Y||Y||-|
|8.||Canon G9 X||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|14.||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 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 G7X) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
The 645Z is a recent model that features in the current product line-up of Pentax. In contrast, the G7X has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the G7X was succeeded 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 conclusions can be drawn? Is the Canon G7 X better than the Pentax 645Z or vice versa? A synthesis of the relative strong points of each of the models is listed below.
Advantages of the Canon PowerShot G7 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).
- 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 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 (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 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 5 months after the 645Z).
Arguments in favor of 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 (30 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (3 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (2 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (3 stops ISO advantage).
- Better sound: Can connect to an external microphone for higher quality sound recording.
- 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.
- 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 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.
- 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 645Z is the clear winner of the contest (19 : 14 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 G7 X 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 the spec-sheets of cameras can offer a general idea of their imaging potential, it remains incomplete and does no justice, for example, to the way the G7X or the 645Z perform in practice. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.
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 G7 X||4/5||+ +||77/100||4.5/5||4.5/5||Sep 2014||699|
|2.||Pentax 645Z||5/5||..||..||4.5/5||5/5||Apr 2014||8,499|
|3.||Canon G7 X Mark II||4.5/5||+ +||81/100||4.5/5||4.5/5||Feb 2016||699|
|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 750D||5/5||..||75/100||4.5/5||4.5/5||Feb 2015||749|
|7.||Canon G5 X||5/5||+ +||78/100||4.5/5||4.5/5||Oct 2015||799|
|8.||Canon G9 X||3.5/5||+ +||..||4.5/5||4.5/5||Oct 2015||529|
|9.||Canon M3||4/5||o||75/100||4.5/5||4/5||Feb 2015||679|
|10.||Canon M10||..||..||..||..||4/5||Oct 2015||499|
|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.||Pentax 645D||5/5||..||..||..||..||Mar 2010||9,995|
|14.||Sony RX100 IV||4.5/5||+ +||85/100||4/5||4.5/5||Jun 2015||999|
|15.||Sony A6000||5/5||+||80/100||4.5/5||5/5||Feb 2014||599|
|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.|
The above review scores should be interpreted with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. A score, therefore, has to be seen in close connection to the price and market introduction time of the camera, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. 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? In case you would like to check on the differences and similarities of other camera models, just make your choice using the following search menu. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Canon G7 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 G7 X||Pentax 645Z|
|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||April 2014|
|Launch Price||USD 699||USD 8,499|
|Sensor Specs||Canon G7 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|
|Image Processor||DIGIC 6||PRIME III|
|DXO Sensor Quality (score)||71||101|
|DXO Color Depth (bits)||23.0||26.0|
|DXO Dynamic Range (EV)||12.7||14.7|
|DXO Low Light (ISO)||556||4505|
|Screen Specs||Canon G7 X||Pentax 645Z|
|Viewfinder Type||no viewfinder||Optical viewfinder|
|Viewfinder Field of View||98%|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.2inch|
|LCD Resolution||1040k dots||1037k dots|
|LCD Attachment||Tilting screen||Tilting screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Canon G7 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||6.5 shutter flaps/s||3 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||UHS-I|
|Connectivity Specs||Canon G7 X||Pentax 645Z|
|External Flash||no Hotshoe||Hotshoe|
|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|
|Body Specs||Canon G7 X||Pentax 645Z|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||210 shots per charge||650 shots per charge|
103 x 60 x 40 mm
(4.1 x 2.4 x 1.6 in)
156 x 117 x 123 mm
(6.1 x 4.6 x 4.8 in)
|Camera Weight||304 g (10.7 oz)||1550 g (54.7 oz)|
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