Canon 5D Mark III vs Pentax 645D
The Canon EOS 5D Mark III and the Pentax 645D are two professional cameras that were revealed to the public, respectively, in March 2012 and March 2010. Both are DSLR (Digital Single Lens Reflex) cameras that are based on a full frame (5D Mark III) and a medium format (645D) sensor. The Canon has a resolution of 22.1 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.
|Canon 5D Mark III||Pentax 645D|
|Digital single lens reflex||Digital single lens reflex|
|Canon EF mount lenses||Pentax 645 mount lenses|
|22.1 MP, Full Frame Sensor||39.5 MP, Medium Format Sensor|
|1080/30p Video||no Video|
|ISO 100-25600 (50-102400)||ISO 100-1600|
|Optical viewfinder||Optical viewfinder|
|3.2" LCD, 1040k dots||3.0" LCD, 921k dots|
|Fixed screen (not touch-sensitive)||Fixed screen (not touch-sensitive)|
|6 shutter flaps per second||1.1 shutter flaps per second|
|Weathersealed body||Weathersealed body|
|950 shots per battery charge||800 shots per battery charge|
|152 x 116 x 76 mm, 950 g||156 x 117 x 119 mm, 1480 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS 5D Mark III 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 side-by-side display below illustrates the physical size and weight of the Canon 5D Mark III and the Pentax 645D. 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.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax 645D is somewhat larger (4 percent) than the Canon 5D Mark III. Moreover, the 645D is substantially heavier (56 percent) than the 5D 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 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 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, just use the right or left arrows in the table to switch to the respective camera. Alternatively, you can also navigate to the CAM-parator app and make your selection from the full list of cameras there.
|Canon 5D Mark III»||152 mm||116 mm||76 mm||950 g||950||Y||Mar 2012||3,499||Canon 5D Mark III|
|Pentax 645D«||156 mm||117 mm||119 mm||1480 g||800||Y||Mar 2010||9,995||Pentax 645D|
|Canon 6D Mark II« »||144 mm||111 mm||75 mm||765 g||1200||Y||Jun 2017||1,999||Canon 6D Mark II|
|Canon 1D X Mark II« »||158 mm||168 mm||83 mm||1530 g||1210||Y||Feb 2016||5,999||Canon 1D X Mark II|
|Canon 5D Mark IV« »||151 mm||116 mm||76 mm||890 g||900||Y||Aug 2016||3,499||Canon 5D Mark IV|
|Canon 5DS« »||152 mm||116 mm||76 mm||930 g||700||Y||Feb 2015||3,699||Canon 5DS|
|Canon 5DS R« »||152 mm||116 mm||76 mm||930 g||700||Y||Feb 2015||3,699||Canon 5DS R|
|Canon 7D II« »||149 mm||112 mm||78 mm||910 g||670||Y||Sep 2014||1,799||Canon 7D II|
|Canon 70D« »||139 mm||104 mm||79 mm||755 g||920||Y||Jul 2013||1,199||Canon 70D|
|Canon 6D« »||145 mm||111 mm||71 mm||770 g||1090||Y||Sep 2012||2,099||Canon 6D|
|Canon 1D X« »||158 mm||168 mm||83 mm||1551 g||1120||Y||Oct 2011||6,799||Canon 1D X|
|Canon 1D Mark IV« »||156 mm||157 mm||80 mm||1230 g||1500||Y||Oct 2009||4,999||Canon 1D Mark IV|
|Canon 5D Mark II« »||152 mm||114 mm||75 mm||850 g||850||Y||Sep 2008||3,499||Canon 5D Mark II|
|Canon 5D« »||152 mm||113 mm||75 mm||895 g||400||Y||Aug 2005||3,299||Canon 5D|
|Leica S Typ 006« »||160 mm||120 mm||80 mm||1260 g||..||Y||Sep 2012||21,950||Leica S Typ 006|
|Nikon D3S« »||160 mm||157 mm||88 mm||1240 g||4200||Y||Oct 2009||5,199||Nikon D3S|
|Pentax 645Z« »||156 mm||117 mm||123 mm||1550 g||650||Y||Apr 2014||8,499||Pentax 645Z|
|Note: Measurements and pricing do not include easily detachable parts, such as interchangeable lenses or optional viewfinders.|
Any camera decision will obviously take relative prices into account. 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 5D Mark III was launched at a markedly lower price (by 65 percent) than the 645D, which puts it into a different market segment. 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.
The size of the imaging sensor is a crucial determinant of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units in a sensor of the same technological generation. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its 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 5D Mark III features a full frame sensor and the Pentax 645D a medium format sensor. The sensor area in the 645D is 68 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 0.79. The sensor in the 5D Mark III 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 5D Mark III (22.1MP), but the 645D has smaller individual pixels (pixel pitch of 6.06μm versus 6.25μm for the 5D Mark III). It is noteworthy in this context that the 5D Mark III is a somewhat more recent model (by 1 year and 11 months) than the 645D, and its sensor might have benefitted from technological advances during this time that further 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 inch or 92.3 x 69.1 cm, for very good quality (250 dpi) 29.1 x 21.8 inch or 73.8 x 55.3 cm, and for excellent quality (300 dpi) 24.2 x 18.1 inch or 61.5 x 46.1 cm. The corresponding values for the Canon 5D Mark III are 28.8 x 19.2 inch or 73.2 x 48.8 cm for good quality, 23 x 15.4 inch or 58.5 x 39 cm for very good quality, and 19.2 x 12.8 inch or 48.8 x 32.5 cm for excellent quality prints.
The Canon EOS 5D Mark III has a native sensitivity range from ISO 100 to ISO 25600, which can be extended to ISO 50-102400. 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"). The Overall DXO ratings for the two cameras under consideration are close, suggesting that they provide similar imaging performance. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
|Canon 5D Mark III||Full Frame||22.1||5760||3840||1080/30p||24.0||11.7||2293||81||Canon 5D Mark III|
|Pentax 645D||Medium Format||39.5||7264||5440||none||24.6||12.6||1262||82||Pentax 645D|
|Canon 6D Mark II||Full Frame||26.0||6240||4160||1080/60p||24.4||11.9||2862||85||Canon 6D Mark II|
|Canon 1D X Mark II||Full Frame||20.0||5472||3648||4K/60p||24.1||13.5||3207||88||Canon 1D X Mark II|
|Canon 5D Mark IV||Full Frame||30.1||6720||4480||4K/30p||24.8||13.6||2995||91||Canon 5D Mark IV|
|Canon 5DS||Full Frame||50.3||8688||5792||1080/30p||24.7||12.4||2381||87||Canon 5DS|
|Canon 5DS R||Full Frame||50.3||8688||5792||1080/30p||24.6||12.4||2308||86||Canon 5DS R|
|Canon 7D II||APS-C||20.0||5472||3648||1080/60p||22.4||11.8||1082||70||Canon 7D II|
|Canon 70D||APS-C||20.0||5472||3648||1080/30p||22.5||11.6||926||68||Canon 70D|
|Canon 6D||Full Frame||20.0||5472||3648||1080/30p||23.8||12.1||2340||82||Canon 6D|
|Canon 1D X||Full Frame||17.9||5184||3456||1080/30p||23.8||11.8||2786||82||Canon 1D X|
|Canon 1D Mark IV||APS-H||16.0||4896||3264||1080/30p||22.8||12.0||1320||74||Canon 1D Mark IV|
|Canon 5D Mark II||Full Frame||21.0||5616||3744||1080/30p||23.7||11.9||1815||79||Canon 5D Mark II|
|Canon 5D||Full Frame||12.7||4368||2912||none||22.9||11.1||1368||71||Canon 5D|
|Leica S Typ 006||Medium Format||37.5||7500||5000||none||23.9||12.2||824||76||Leica S Typ 006|
|Nikon D3S||Full Frame||12.1||4256||2832||720/24p||23.5||12.0||3253||82||Nikon D3S|
|Pentax 645Z||Medium Format||51.1||8256||6192||1080/60i||26.0||14.7||4505||101||Pentax 645Z|
Many modern cameras cannot only take still pictures, but also record videos. The 5D Mark III indeed provides movie recording capabilities, while the 645D does not. The highest resolution format that the 5D Mark III can use is 1080/30p.
Apart from body and sensor, cameras can and do differ across a variety of features. The 5D Mark III and the 645D are similar in the sense that both have an optical viewfinder. The latter is useful for getting a clear image for framing even in brightly lit environments. The viewfinder in the 5D Mark III offers a wider field of view (100%) than the one in the 645D (98%), so that a larger proportion of the captured image is visible in the finder. On the other hand, the viewfinder of the 645D has a higher magnification (0.78x vs 0.71x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The table below summarizes some of the other core capabilities of the Canon 5D Mark III and Pentax 645D in connection with corresponding information for a sample of similar cameras.
|Canon 5D Mark III||optical||Y||3.2||1040||fixed||n||1/8000s||6.0||n||n||Canon 5D Mark III|
|Pentax 645D||optical||Y||3.0||921||fixed||n||1/4000s||1.1||n||n||Pentax 645D|
|Canon 6D Mark II||optical||Y||3.0||1040||swivel||Y||1/4000s||6.5||n||n||Canon 6D Mark II|
|Canon 1D X Mark II||optical||Y||3.2||1620||fixed||Y||1/8000s||16.0||n||n||Canon 1D X Mark II|
|Canon 5D Mark IV||optical||Y||3.2||1620||fixed||Y||1/8000s||7.0||n||n||Canon 5D Mark IV|
|Canon 5DS||optical||Y||3.2||1040||fixed||n||1/8000s||5.0||n||n||Canon 5DS|
|Canon 5DS R||optical||Y||3.2||1040||fixed||n||1/8000s||5.0||n||n||Canon 5DS R|
|Canon 7D II||optical||Y||3.0||1040||fixed||n||1/8000s||10.0||Y||n||Canon 7D II|
|Canon 70D||optical||Y||3.0||1040||swivel||Y||1/8000s||7.0||Y||n||Canon 70D|
|Canon 6D||optical||Y||3.0||1040||fixed||n||1/4000s||4.5||n||n||Canon 6D|
|Canon 1D X||optical||Y||3.2||1040||fixed||n||1/8000s||14.0||n||n||Canon 1D X|
|Canon 1D Mark IV||optical||Y||3.0||920||fixed||n||1/8000s||10.0||n||n||Canon 1D Mark IV|
|Canon 5D Mark II||optical||Y||3.0||920||fixed||n||1/8000s||3.9||n||n||Canon 5D Mark II|
|Canon 5D||optical||Y||2.5||230||fixed||n||1/8000s||3.0||n||n||Canon 5D|
|Leica S Typ 006||optical||Y||3.0||922||fixed||n||1/4000s||1.5||n||n||Leica S Typ 006|
|Nikon D3S||optical||Y||3.0||921||fixed||n||1/8000s||11.0||n||n||Nikon D3S|
|Pentax 645Z||optical||Y||3.2||1037||tilting||n||1/4000s||3.0||n||n||Pentax 645Z|
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.
The 5D Mark III writes its imaging data to Compact Flash or SDXC cards, while the 645D uses SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails.
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 5D Mark III and Pentax 645D and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
|Canon 5D Mark III||Y||mono||mono||Y||Y||mini||2.0||-||-||-||Canon 5D Mark III|
|Pentax 645D||Y||stereo||none||-||-||none||2.0||-||-||-||Pentax 645D|
|Canon 6D Mark II||Y||stereo||mono||Y||-||mini||2.0||Y||Y||Y||Canon 6D Mark II|
|Canon 1D X Mark II||Y||mono||mono||Y||Y||mini||3.0||-||-||-||Canon 1D X Mark II|
|Canon 5D Mark IV||Y||mono||mono||Y||Y||mini||3.0||Y||Y||-||Canon 5D Mark IV|
|Canon 5DS||Y||mono||mono||Y||-||mini||3.0||-||-||-||Canon 5DS|
|Canon 5DS R||Y||mono||mono||Y||-||mini||3.0||-||-||-||Canon 5DS R|
|Canon 7D II||Y||stereo||mono||Y||Y||mini||3.0||-||-||-||Canon 7D II|
|Canon 70D||Y||stereo||mono||Y||-||mini||2.0||Y||-||-||Canon 70D|
|Canon 6D||Y||mono||mono||Y||-||mini||2.0||Y||-||-||Canon 6D|
|Canon 1D X||Y||mono||none||Y||-||mini||2.0||-||-||-||Canon 1D X|
|Canon 1D Mark IV||Y||stereo||none||Y||-||mini||2.0||-||-||-||Canon 1D Mark IV|
|Canon 5D Mark II||Y||mono||mono||Y||-||mini||2.0||-||-||-||Canon 5D Mark II|
|Canon 5D||Y||none||none||-||-||none||2.0||-||-||-||Canon 5D|
|Leica S Typ 006||Y||none||none||-||-||mini||2.0||-||-||-||Leica S Typ 006|
|Nikon D3S||Y||stereo||none||-||-||mini||2.0||-||-||-||Nikon D3S|
|Pentax 645Z||Y||stereo||mono||Y||-||mini||3.0||-||-||-||Pentax 645Z|
Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.
Both the 5D Mark III and the 645D have been discontinued, but can regularly be found used on eBay. The 645D was replaced by the Pentax 645Z, while the 5D Mark III was followed by the Canon 5D Mark IV. 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? Which of the two cameras – the Canon 5D Mark III or the Pentax 645D – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.
Advantages of the Canon EOS 5D Mark III:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Better low-light sensitivity: Requires less light for good images (0.9 stops ISO advantage).
- Broader imaging potential: Can record not only still images but also 1080/30p movies.
- More complete view: Has a viewfinder with a larger field of view (100% vs 98%).
- Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
- More detailed LCD: Has a higher resolution rear screen (1040k vs 921k dots).
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (6 vs 1.1 flaps/sec) to capture the decisive moment.
- Less heavy: Is lighter (by 530g or 36 percent) and hence easier to carry around.
- Longer lasting: Can take more shots (950 versus 800) on a single battery charge.
- More affordable: Was introduced into a lower priced category (65 percent cheaper at launch).
- More modern: Is somewhat more recent (announced 1 year and 11 months after the 645D).
Reasons to prefer the Pentax 645D:
- More detail: Has more megapixels (39.5 vs 22.1MP), which boosts linear resolution by 31%.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- More dynamic range: Captures a broader range of light and dark details (0.9 EV of extra DR).
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.71x).
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More heavily discounted: Has been on the market for longer (launched in March 2010).
If the count of individual advantages (bullet points above) is taken as a guide, the 5D Mark III is the clear winner of the match-up (12 : 6 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 sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape 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 5D Mark III and the Pentax 645D place the cameras among the top in their class? Find out in the latest Best DSLR Camera listing 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 remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the 5D Mark III or the 645D. 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 (cameralabs, dpreview, ephotozine, imaging-resource, and photographyblog). 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.
The review scores listed above should be treated 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 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. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
- Canon 1D Mark II N vs Canon 5D Mark III
- Canon 5D Mark III vs Fujifilm X-Pro1
- Canon 5D Mark III vs Nikon D300
- Canon 5D Mark III vs Nikon D3S
- Canon 5D Mark III vs Olympus E-30
- Canon 5D Mark III vs Olympus E-500
- Canon 5D Mark III vs Panasonic G90
- Canon 5D Mark III vs Sony RX1R II
- Leica S3 vs Pentax 645D
- Nikon 1 J4 vs Pentax 645D
- Pentax 645D vs Sony A7 III
- Pentax 645D vs Sony RX1
Specifications: Canon 5D Mark III 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 5D Mark III||Pentax 645D|
|Camera Type||Digital single lens reflex||Digital single lens reflex|
|Camera Lens||Canon EF mount lenses||Pentax 645 mount lenses|
|Launch Date||March 2012||March 2010|
|Launch Price||USD 3499||USD 9995|
|Sensor Specs||Canon 5D Mark III||Pentax 645D|
|Sensor Format||Full Frame Sensor||Medium Format Sensor|
|Sensor Size||36.0 x 24.0 mm||44.0 x 33.0 mm|
|Sensor Area||864 mm2||1452 mm2|
|Sensor Diagonal||43.3 mm||55 mm|
|Sensor Resolution||22.1 Megapixels||39.5 Megapixels|
|Image Resolution||5760 x 3840 pixels||7264 x 5440 pixels|
|Pixel Pitch||6.25 μm||6.06 μm|
|Pixel Density||2.56 MP/cm2||2.72 MP/cm2|
|Moiré control||Anti-Alias filter||no AA filter|
|Movie Capability||1080/30p Video||no Video|
|ISO Setting||100-25600 ISO||100-1600 ISO|
|ISO Boost||50-102400 ISO||no Enhancement|
|Image Processor||DIGIC 5+||PRIME II|
|DXO Sensor Quality (score)||81||82|
|DXO Color Depth (bits)||24.0||24.6|
|DXO Dynamic Range (EV)||11.7||12.6|
|DXO Low Light (ISO)||2293||1262|
|Screen Specs||Canon 5D Mark III||Pentax 645D|
|Viewfinder Type||Optical viewfinder||Optical viewfinder|
|Viewfinder Field of View||100%||98%|
|Top-Level Screen||Control Panel||Control Panel|
|LCD Framing||Live View|
|Rear LCD Size||3.2 inch||3.0 inch|
|LCD Resolution||1040k dots||921k dots|
|LCD Attachment||Fixed screen||Fixed screen|
|Shooting Specs||Canon 5D Mark III||Pentax 645D|
|Focus System||Phase-detect AF||Phase-detect AF|
|Continuous Shooting||6 shutter flaps/s||1.1 shutter flaps/s|
|Shutter Life Expectancy||150 000 actuations||50 000 actuations|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|Fill Flash||no On-Board Flash||no On-Board Flash|
|Storage Medium||CF or SDXC cards||SDXC cards|
|Second Storage Option||Dual card slots||Dual card slots|
|UHS card support||no||no|
|Connectivity Specs||Canon 5D Mark III||Pentax 645D|
|Studio Flash||PC Sync socket||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|
|Headphone Socket||Headphone port||no Headphone port|
|Wifi Support||no Wifi||no Wifi|
|Body Specs||Canon 5D Mark III||Pentax 645D|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||950 shots per charge||800 shots per charge|
152 x 116 x 76 mm
(6.0 x 4.6 x 3.0 in)
156 x 117 x 119 mm
(6.1 x 4.6 x 4.7 in)
|Camera Weight||950 g (33.5 oz)||1480 g (52.2 oz)|
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