Olympus E-M5 vs Pentax 645D
The Olympus OM-D E-M5 and the Pentax 645D are two digital cameras that were revealed to the public, respectively, in February 2012 and March 2010. The E-M5 is a mirrorless interchangeable lens camera, while the 645D is a DSLR. The cameras are based on a Four Thirds (E-M5) and a medium format (645D) sensor. The Olympus has a resolution of 15.9 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 Olympus OM-D E-M5 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 Olympus E-M5 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 E-M5 can be obtained in two different colors (black, silver), 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 (68 percent) than the Olympus E-M5. Moreover, the 645D is substantially heavier (248 percent) than the E-M5. 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 adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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.||Olympus E-M5||122 mm||89 mm||43 mm||425 g||360||Y||Feb 2012||1,299|
|2.||Pentax 645D||156 mm||117 mm||119 mm||1480 g||800||Y||Mar 2010||9,995|
|3.||Canon 1D X||158 mm||168 mm||83 mm||1551 g||1120||Y||Oct 2011||6,799|
|4.||Canon 1D Mark IV||156 mm||157 mm||80 mm||1230 g||1500||Y||Oct 2009||4,999|
|5.||Leica S Typ 006||160 mm||120 mm||80 mm||1260 g||..||Y||Sep 2012||21,950|
|6.||Nikon D3S||160 mm||157 mm||88 mm||1240 g||4200||Y||Oct 2009||5,199|
|7.||Olympus PEN-F||125 mm||72 mm||37 mm||427 g||330||n||Jan 2016||1,199|
|8.||Olympus E-M5 II||124 mm||85 mm||45 mm||469 g||310||Y||Feb 2015||1,099|
|9.||Olympus E-PL7||115 mm||67 mm||38 mm||357 g||350||n||Aug 2014||599|
|10.||Olympus E-M1||130 mm||94 mm||63 mm||497 g||350||Y||Sep 2013||1,399|
|11.||Olympus E-P5||122 mm||69 mm||37 mm||420 g||330||n||May 2013||999|
|12.||Olympus E-PL5||111 mm||64 mm||38 mm||325 g||360||n||Sep 2012||599|
|13.||Olympus E-PM2||110 mm||64 mm||34 mm||269 g||360||n||Sep 2012||499|
|14.||Panasonic GX8||133 mm||78 mm||63 mm||487 g||330||Y||Jul 2015||1,199|
|15.||Panasonic GX7||123 mm||71 mm||55 mm||402 g||350||n||Aug 2013||999|
|16.||Panasonic GH3||133 mm||93 mm||82 mm||550 g||540||Y||Sep 2012||1,299|
|17.||Pentax 645Z||156 mm||117 mm||123 mm||1550 g||650||Y||Apr 2014||8,499|
Any camera decision will naturally be influenced heavily by the price. 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 E-M5 was launched at a markedly lower price (by 87 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 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 more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Olympus E-M5 features a Four Thirds sensor and the Pentax 645D a medium format sensor. The sensor area in the 645D is 545 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 0.79. Both cameras feature a native aspect ratio (sensor width to sensor height) of 4:3.
With 39.5MP, the 645D offers a higher resolution than the E-M5 (15.9MP), but the 645D nevertheless has larger individual pixels (pixel pitch of 6.06μm versus 3.76μm for the E-M5) due to its larger sensor. However, the E-M5 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 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 Olympus E-M5 are 23 x 17.3 inches or 58.5 x 43.9 cm for good quality, 18.4 x 13.8 inches or 46.8 x 35.1 cm for very good quality, and 15.4 x 11.5 inches or 39 x 29.3 cm for excellent quality prints.
The Olympus OM-D E-M5 has a native sensitivity range from ISO 200 to ISO 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 offers substantially better image quality than the E-M5 (overall score 11 points higher). The advantage is based on 1.8 bits higher color depth, 0.3 EV in additional dynamic range, and 0.6 stops in additional low light sensitivity. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
| DXO |
|1.||Olympus E-M5||Four Thirds||15.9||4608||3456||1080/60i||22.8||12.3||826||71|
|2.||Pentax 645D||Medium Format||39.5||7264||5440||none||24.6||12.6||1262||82|
|3.||Canon 1D X||Full Frame||17.9||5184||3456||1080/30p||23.8||11.8||2786||82|
|4.||Canon 1D Mark IV||APS-H||16.0||4896||3264||1080/30p||22.8||12.0||1320||74|
|5.||Leica S Typ 006||Medium Format||37.5||7500||5000||none||23.9||12.2||824||76|
|6.||Nikon D3S||Full Frame||12.1||4256||2832||720/24p||23.5||12.0||3253||82|
|7.||Olympus PEN-F||Four Thirds||20.2||5184||3888||1080/60p||23.1||12.4||894||74|
|8.||Olympus E-M5 II||Four Thirds||15.9||4608||3456||1080/60p||23.0||12.5||842||73|
|9.||Olympus E-PL7||Four Thirds||15.9||4608||3456||1080/30p||22.7||12.4||873||72|
|10.||Olympus E-M1||Four Thirds||15.9||4608||3456||1080/30p||23.0||12.7||757||73|
|11.||Olympus E-P5||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.4||895||72|
|12.||Olympus E-PL5||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.3||889||72|
|13.||Olympus E-PM2||Four Thirds||15.9||4608||3456||1080/30p||22.7||12.2||932||72|
|14.||Panasonic GX8||Four Thirds||20.2||5184||3888||4K/30p||23.5||12.6||806||75|
|15.||Panasonic GX7||Four Thirds||15.8||4592||3448||1080/60p||22.6||12.2||718||70|
|16.||Panasonic GH3||Four Thirds||15.9||4608||3456||1080/60p||22.7||12.4||812||71|
|17.||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 also of capturing video footage. The E-M5 indeed provides movie recording capabilities, while the 645D does not. The highest resolution format that the E-M5 can use is 1080/60i.
Apart from body and sensor, cameras can and do differ across a variety of features. For example, the E-M5 has an electronic viewfinder (1440k dots), while the 645D 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 viewfinder in the E-M5 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 0.58x), 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 Olympus E-M5 and Pentax 645D in connection with corresponding information for a sample of similar cameras.
|3.||Canon 1D X||optical||Y||3.2||1040||fixed||n||1/8000s||14.0||n||n|
|4.||Canon 1D Mark IV||optical||Y||3.0||920||fixed||n||1/8000s||10.0||n||n|
|5.||Leica S Typ 006||optical||Y||3.0||922||fixed||n||1/4000s||1.5||n||n|
|8.||Olympus E-M5 II||2360||n||3.0||1037||swivel||Y||1/8000s||10.0||n||Y|
One feature that differentiates the E-M5 and the 645D is in-body image stabilization (IBIS). The E-M5 reduces the risk of handshake-induced blur with all attached lenses, while the 645D offers no blur reduction with lenses that themselves do not provide optical image stabilization.
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 E-M5 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 E-M5 only has one slot. The E-M5 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 Olympus OM-D E-M5 and Pentax 645D and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|3.||Canon 1D X||Y||mono||-||Y||-||mini||2.0||-||-||-|
|4.||Canon 1D Mark IV||Y||stereo||-||Y||-||mini||2.0||-||-||-|
|5.||Leica S Typ 006||Y||-||-||-||-||mini||2.0||-||-||-|
|8.||Olympus E-M5 II||Y||stereo||mono||Y||-||micro||2.0||Y||-||-|
Studio photographers will appreciate that the Pentax 645D (unlike the E-M5) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the E-M5 and the 645D have been discontinued, but can regularly be found used on eBay. The 645D was replaced by the Pentax 645Z, while the E-M5 was followed by the Olympus E-M5 II. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Olympus and Pentax websites.
So what conclusions can be drawn? Is the Olympus E-M5 better than the Pentax 645D or vice versa? A synthesis of the relative strong points of each of the models is listed below.
Reasons to prefer the Olympus OM-D E-M5:
- 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 1080/60i movies.
- More framing info: Has an electronic viewfinder that displays shooting data.
- More complete view: Has a viewfinder with a larger field of view (100% vs 98%).
- 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.
- Faster burst: Shoots at higher frequency (9 vs 1.1 flaps/sec) to capture the decisive moment.
- More compact: Is smaller (122x89mm vs 156x117mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 1055g or 71 percent) and hence easier to carry around.
- Sharper images: Has hand-shake reducing image stabilization built-in.
- More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
- Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
- More affordable: Was introduced into a lower priced category (87 percent cheaper at launch).
- More modern: Is somewhat more recent (announced 1 year and 11 months after the 645D).
Advantages of the Pentax 645D:
- More detail: Has more megapixels (39.5 vs 15.9MP), which boosts linear resolution by 58%.
- 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 (1.8 bits more color depth).
- Better low-light sensitivity: Can shoot in dim conditions (0.6 stops ISO advantage).
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.58x).
- Easier setting verification: Features a control panel on top to check shooting parameters.
- More detailed LCD: Has a higher resolution rear screen (921k vs 610k dots).
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Longer lasting: Gets more shots (800 versus 360) out of a single battery charge.
- 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 March 2010).
If the count of relative strengths (bullet points above) is taken as a measure, the match-up finishes in a tie (14 points each). 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 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 Olympus E-M5 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it says little about, for example, the shooting experience and imaging performance of the E-M5 and the 645D in practical situations. 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 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.||Olympus E-M5||4/5||+ +||80/100||4.5/5||5/5||Feb 2012||1,299|
|2.||Pentax 645D||5/5||..||..||..||..||Mar 2010||9,995|
|3.||Canon 1D X||5/5||..||..||4.5/5||4.5/5||Oct 2011||6,799|
|4.||Canon 1D Mark IV||5/5||..||89/100||..||..||Oct 2009||4,999|
|5.||Leica S Typ 006||..||..||..||..||..||Sep 2012||21,950|
|6.||Nikon D3S||5/5||..||89/100||4.5/5||5/5||Oct 2009||5,199|
|7.||Olympus PEN-F||..||..||82/100||4.5/5||5/5||Jan 2016||1,199|
|8.||Olympus E-M5 II||5/5||+ +||81/100||5/5||5/5||Feb 2015||1,099|
|9.||Olympus E-PL7||4/5||+||..||5/5||4/5||Aug 2014||599|
|10.||Olympus E-M1||5/5||+ +||84/100||4.5/5||4.5/5||Sep 2013||1,399|
|11.||Olympus E-P5||5/5||+ +||78/100||4.5/5||5/5||May 2013||999|
|12.||Olympus E-PL5||3/5||+ +||..||4.5/5||4.5/5||Sep 2012||599|
|13.||Olympus E-PM2||3/5||..||77/100||5/5||4.5/5||Sep 2012||499|
|14.||Panasonic GX8||5/5||+||82/100||4.5/5||4.5/5||Jul 2015||1,199|
|15.||Panasonic GX7||4/5||+||79/100||5/5||5/5||Aug 2013||999|
|16.||Panasonic GH3||5/5||+ +||79/100||4.5/5||4.5/5||Sep 2012||1,299|
|17.||Pentax 645Z||5/5||..||..||4.5/5||5/5||Apr 2014||8,499|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The review scores listed above should be treated with care, though. The assessments were made in relation to similar cameras of the same technological generation. 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. 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 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.
Specifications: Olympus E-M5 vs Pentax 645D
|Camera Model||Olympus E-M5||Pentax 645D|
|Camera Type||Mirrorless system camera||Digital single lens reflex|
|Camera Lens||Micro Four Thirds lenses||Pentax 645 mount lenses|
|Launch Date||February 2012||March 2010|
|Launch Price||USD 1,299||USD 9,995|
|Sensor Specs||Olympus E-M5||Pentax 645D|
|Sensor Format||Four Thirds Sensor||Medium Format Sensor|
|Sensor Size||17.3 x 13.0 mm||44.0 x 33.0 mm|
|Sensor Area||224.9 mm2||1452 mm2|
|Sensor Diagonal||21.6 mm||55 mm|
|Sensor Resolution||15.9 Megapixels||39.5 Megapixels|
|Image Resolution||4608 x 3456 pixels||7264 x 5440 pixels|
|Pixel Pitch||3.76 μm||6.06 μm|
|Pixel Density||7.08 MP/cm2||2.72 MP/cm2|
|Moiré control||Anti-Alias filter||no AA filter|
|Movie Capability||1080/60i Video||no Video|
|ISO Setting||200 - 25,600 ISO||100 - 1,600 ISO|
|Image Processor||TruePic VI||PRIME II|
|DXO Sensor Quality (score)||71||82|
|DXO Color Depth (bits)||22.8||24.6|
|DXO Dynamic Range (EV)||12.3||12.6|
|DXO Low Light (ISO)||826||1262|
|Screen Specs||Olympus E-M5||Pentax 645D|
|Viewfinder Type||Electronic viewfinder||Optical viewfinder|
|Viewfinder Field of View||100%||98%|
|Viewfinder Resolution||1440k dots|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||610k dots||921k dots|
|LCD Attachment||Tilting screen||Fixed screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Olympus E-M5||Pentax 645D|
|Focus System||Contrast-detect AF||Phase-detect AF|
|Continuous Shooting||9 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|
|Image Stabilization||In-body stabilization||Lens stabilization only|
|Fill Flash||no On-Board 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||Olympus E-M5||Pentax 645D|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||mini HDMI||no HDMI|
|Wifi Support||no Wifi||no Wifi|
|Body Specs||Olympus E-M5||Pentax 645D|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||360 shots per charge||800 shots per charge|
122 x 89 x 43 mm
(4.8 x 3.5 x 1.7 in)
156 x 117 x 119 mm
(6.1 x 4.6 x 4.7 in)
|Camera Weight||425 g (15.0 oz)||1480 g (52.2 oz)|