Canon M3 vs Pentax 645D
The Canon EOS M3 and the Pentax 645D are two digital cameras that were officially introduced, respectively, in February 2015 and March 2010. The M3 is a mirrorless interchangeable lens camera, while the 645D is a DSLR. The cameras are based on an APS-C (M3) and a medium format (645D) sensor. The Canon has a resolution of 24 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 EOS M3 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.
The physical size and weight of the Canon M3 and the Pentax 645D are illustrated in the side-by-side display below. 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 measures are rounded to the nearest millimeter.
The M3 can be obtained in two different colors (black, white), while the 645D 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 645D is considerably larger (142 percent) than the Canon M3. Moreover, the 645D is substantially heavier (304 percent) than the M3. It is noteworthy in this context that the 645D is splash and dust-proof, while the M3 does not feature any corresponding weather-sealing.
The above size and weight comparisons are to some extent incomplete since they do not consider the interchangeable lenses that both of these cameras require. Hence, you might want to study and compare the specifications of available lenses in order to get the full picture of the size and weight of the two camera systems.
The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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 M3||111 mm||68 mm||44 mm||366 g||250||n||Feb 2015||679|
|2.||Pentax 645D||156 mm||117 mm||119 mm||1480 g||800||Y||Mar 2010||9,995|
|3.||Canon M6||112 mm||68 mm||45 mm||390 g||295||n||Feb 2017||779|
|4.||Canon M100||108 mm||67 mm||35 mm||302 g||295||n||Aug 2017||499|
|5.||Canon G7 X Mark II||106 mm||61 mm||42 mm||319 g||265||n||Feb 2016||699|
|6.||Canon M5||116 mm||89 mm||61 mm||427 g||295||n||Sep 2016||979|
|7.||Canon 750D||132 mm||101 mm||78 mm||555 g||440||n||Feb 2015||749|
|8.||Canon G5 X||112 mm||76 mm||44 mm||353 g||210||n||Oct 2015||799|
|9.||Canon M10||108 mm||67 mm||35 mm||301 g||255||n||Oct 2015||499|
|10.||Canon G7 X||103 mm||60 mm||40 mm||304 g||210||n||Sep 2014||699|
|11.||Canon M||109 mm||66 mm||32 mm||298 g||230||n||Jul 2012||599|
|12.||Canon 1D X||158 mm||168 mm||83 mm||1551 g||1120||Y||Oct 2011||6,799|
|13.||Canon 1D Mark IV||156 mm||157 mm||80 mm||1230 g||1500||Y||Oct 2009||4,999|
|14.||Leica S Typ 006||160 mm||120 mm||80 mm||1260 g||..||Y||Sep 2012||21,950|
|15.||Nikon D3S||160 mm||157 mm||88 mm||1240 g||4200||Y||Oct 2009||5,199|
|16.||Pentax 645Z||156 mm||117 mm||123 mm||1550 g||650||Y||Apr 2014||8,499|
|17.||Sony A6000||120 mm||67 mm||45 mm||344 g||360||n||Feb 2014||599|
|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 M3 was launched at a markedly lower price (by 93 percent) than the 645D, which puts it into a different market segment. 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. 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Canon M3 features an APS-C sensor and the Pentax 645D a medium format sensor. The sensor area in the 645D is 337 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.6 and 0.79. The sensor in the M3 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 M3 (24MP), but the 645D nevertheless has larger individual pixels (pixel pitch of 6.06μm versus 3.72μm for the M3) due to its larger sensor. However, the M3 is a much more recent model (by 4 years and 10 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 M3 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 M3 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
The Canon EOS M3 has a native sensitivity range from ISO 100 to ISO 12800, which can be extended to ISO 100-25600. The corresponding ISO settings for the Pentax 645D are ISO 100 to ISO 1600 (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 645D has a markedly higher DXO score than the M3 (overall score 10 points higher), which will translate into better image quality. The advantage is based on 1.8 bits higher color depth, 0.8 EV in additional dynamic range, and 0.1 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 |
|2.||Pentax 645D||Medium Format||39.5||7264||5440||none||24.6||12.6||1262||82|
|5.||Canon G7 X Mark II||1-inch||20.0||5472||3648||1080/60p||..||..||..||..|
|8.||Canon G5 X||1-inch||20.0||5472||3648||1080/60p||..||..||..||..|
|10.||Canon G7 X||1-inch||20.0||5472||3648||1080/60p||23.0||12.7||556||71|
|12.||Canon 1D X||Full Frame||17.9||5184||3456||1080/30p||23.8||11.8||2786||82|
|13.||Canon 1D Mark IV||APS-H||16.0||4896||3264||1080/30p||22.8||12.0||1320||74|
|14.||Leica S Typ 006||Medium Format||37.5||7500||5000||none||23.9||12.2||824||76|
|15.||Nikon D3S||Full Frame||12.1||4256||2832||720/24p||23.5||12.0||3253||82|
|16.||Pentax 645Z||Medium Format||51.1||8256||6192||1080/60i||26.0||14.7||4505||101|
Many modern cameras are not only capable of taking still images, but can also record movies. The M3 indeed provides movie recording capabilities, while the 645D does not. The highest resolution format that the M3 can use is 1080/30p.
Apart from body and sensor, cameras can and do differ across a variety of features. For example, the 645D has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the M3 relies on live view and the rear LCD for framing. That said, the M3 can be equipped with an optional viewfinder – the EVF-DC1. The table below summarizes some of the other core capabilities of the Canon M3 and Pentax 645D in connection with corresponding information for a sample of similar cameras.
|5.||Canon G7 X Mark II||none||n||3.0||1040||tilting||Y||1/2000s||8.0||Y||Y|
|8.||Canon G5 X||2360||n||3.0||1040||swivel||Y||1/2000s||5.9||Y||Y|
|10.||Canon G7 X||none||n||3.0||1040||tilting||Y||1/2000s||6.5||Y||Y|
|12.||Canon 1D X||optical||Y||3.2||1040||fixed||n||1/8000s||14.0||n||n|
|13.||Canon 1D Mark IV||optical||Y||3.0||920||fixed||n||1/8000s||10.0||n||n|
|14.||Leica S Typ 006||optical||Y||3.0||922||fixed||n||1/4000s||1.5||n||n|
One difference between the cameras concerns the presence of an on-board flash. The M3 has one, while the 645D does not. While the built-in flash of the M3 is not very powerful, it can at times be useful as a fill-in light.The M3 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 Pentax 645D 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 M3 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 M3 only has one slot. The M3 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 EOS M3 and Pentax 645D and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|5.||Canon G7 X Mark II||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|8.||Canon G5 X||Y||stereo||mono||-||-||mini||2.0||Y||Y||-|
|10.||Canon G7 X||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|12.||Canon 1D X||Y||mono||-||Y||-||mini||2.0||-||-||-|
|13.||Canon 1D Mark IV||Y||stereo||-||Y||-||mini||2.0||-||-||-|
|14.||Leica S Typ 006||Y||-||-||-||-||mini||2.0||-||-||-|
It is notable that the M3 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 M3) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the M3 and the 645D have been discontinued, but can regularly be found used on eBay. The 645D was replaced by the Pentax 645Z, while the M3 was followed by the Canon M6. 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 there a clear favorite between the Canon M3 and the Pentax 645D? Which camera is better? The listing below highlights the relative strengths of the two models.
Advantages of the Canon EOS M3:
- 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 1080/30p movies.
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- 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 (4.2 vs 1.1 flaps/sec) to capture the decisive moment.
- More compact: Is smaller (111x68mm vs 156x117mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 1114g or 75 percent) and hence easier to carry around.
- More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
- 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 into a lower priced category (93 percent cheaper at launch).
- More modern: Reflects 4 years and 10 months of technical progress since the 645D launch.
Reasons to prefer the Pentax 645D:
- More detail: Has more megapixels (39.5 vs 24MP), which boosts linear resolution by 26%.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- Better image quality: Scores markedly higher (10 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (1.8 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (0.8 EV of extra DR).
- 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.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Longer lasting: Gets more shots (800 versus 250) out of a single battery charge.
- Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
- 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 individual advantages (bullet points above) is taken as a guide, the M3 is the clear winner of the match-up (17 : 13 points). 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 M3 and the Pentax 645D place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens 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 M3 or the 645D perform in practice. 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 hands-on reviews by experts 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 M3||4/5||o||75/100||4.5/5||4/5||Feb 2015||679|
|2.||Pentax 645D||5/5||..||..||..||..||Mar 2010||9,995|
|3.||Canon M6||..||..||80/100||4/5||4/5||Feb 2017||779|
|4.||Canon M100||3/5||+||..||4/5||3.5/5||Aug 2017||499|
|5.||Canon G7 X Mark II||4.5/5||+ +||81/100||4.5/5||4.5/5||Feb 2016||699|
|6.||Canon M5||4/5||+||82/100||4/5||4/5||Sep 2016||979|
|7.||Canon 750D||5/5||..||75/100||4.5/5||4.5/5||Feb 2015||749|
|8.||Canon G5 X||5/5||+ +||78/100||4.5/5||4.5/5||Oct 2015||799|
|9.||Canon M10||..||..||..||..||4/5||Oct 2015||499|
|10.||Canon G7 X||4/5||+ +||77/100||4.5/5||4.5/5||Sep 2014||699|
|11.||Canon M||3/5||+||..||4/5||4/5||Jul 2012||599|
|12.||Canon 1D X||5/5||..||..||4.5/5||4.5/5||Oct 2011||6,799|
|13.||Canon 1D Mark IV||5/5||..||89/100||..||..||Oct 2009||4,999|
|14.||Leica S Typ 006||..||..||..||..||..||Sep 2012||21,950|
|15.||Nikon D3S||5/5||..||89/100||4.5/5||5/5||Oct 2009||5,199|
|16.||Pentax 645Z||5/5||..||..||4.5/5||5/5||Apr 2014||8,499|
|17.||Sony A6000||5/5||+||80/100||4.5/5||5/5||Feb 2014||599|
|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. 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. 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 are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Canon M3 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 M3||Pentax 645D|
|Camera Type||Mirrorless system camera||Digital single lens reflex|
|Camera Lens||Canon EF-M mount lenses||Pentax 645 mount lenses|
|Launch Date||February 2015||March 2010|
|Launch Price||USD 679||USD 9,995|
|Sensor Specs||Canon M3||Pentax 645D|
|Sensor Format||APS-C Sensor||Medium Format Sensor|
|Sensor Size||22.3 x 14.9 mm||44.0 x 33.0 mm|
|Sensor Area||332.27 mm2||1452 mm2|
|Sensor Diagonal||26.8 mm||55 mm|
|Sensor Resolution||24 Megapixels||39.5 Megapixels|
|Image Resolution||6000 x 4000 pixels||7264 x 5440 pixels|
|Pixel Pitch||3.72 μm||6.06 μm|
|Pixel Density||7.22 MP/cm2||2.72 MP/cm2|
|Moiré control||Anti-Alias filter||no AA filter|
|Movie Capability||1080/30p Video||no Video|
|ISO Setting||100 - 12,800 ISO||100 - 1,600 ISO|
|ISO Boost||100 - 25,600 ISO||no Enhancement|
|Image Processor||DIGIC 6||PRIME II|
|DXO Sensor Quality (score)||72||82|
|DXO Color Depth (bits)||22.8||24.6|
|DXO Dynamic Range (EV)||11.8||12.6|
|DXO Low Light (ISO)||1169||1262|
|Screen Specs||Canon M3||Pentax 645D|
|Viewfinder Type||Viewfinder optional||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 M3||Pentax 645D|
|Focus System||On-Sensor Phase-detect||Phase-detect AF|
|Manual Focusing Aid||Focus Peaking||no Peaking Feature|
|Continuous Shooting||4.2 shutter flaps/s||1.1 shutter flaps/s|
|Shutter Life Expectancy||100 000 actuations||50 000 actuations|
|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||no|
|Connectivity Specs||Canon M3||Pentax 645D|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||mini HDMI||no HDMI|
|Microphone Port||External MIC port||no MIC socket|
|Wifi Support||Wifi built-in||no Wifi|
|Near-Field Communication||NFC built-in||no NFC|
|Body Specs||Canon M3||Pentax 645D|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||250 shots per charge||800 shots per charge|
111 x 68 x 44 mm
(4.4 x 2.7 x 1.7 in)
156 x 117 x 119 mm
(6.1 x 4.6 x 4.7 in)
|Camera Weight||366 g (12.9 oz)||1480 g (52.2 oz)|
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