Olympus E-PM2 vs Pentax 645D
The Olympus PEN E-PM2 and the Pentax 645D are two digital cameras that were officially introduced, respectively, in September 2012 and March 2010. The E-PM2 is a mirrorless interchangeable lens camera, while the 645D is a DSLR. The cameras are based on a Four Thirds (E-PM2) 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.
|Olympus E-PM2||Pentax 645D|
|Mirrorless system camera||Digital single lens reflex|
|Micro Four Thirds lenses||Pentax 645 mount lenses|
|15.9 MP, Four Thirds Sensor||39.5 MP, Medium Format Sensor|
|1080/30p Video||no Video|
|ISO 100-25,600||ISO 100-1,600|
|Viewfinder optional||Optical viewfinder|
|3.0 LCD, 460k dots||3.0 LCD, 921k dots|
|Fixed touchscreen||Fixed screen (not touch-sensitive)|
|8 shutter flaps per second||1.1 shutter flaps per second|
|In-body stabilization||Lens stabilization only|
|not weather sealed||Weathersealed body|
|360 shots per battery charge||800 shots per battery charge|
|110 x 64 x 34 mm, 269 g||156 x 117 x 119 mm, 1480 g|
Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus PEN E-PM2 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-PM2 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 views from the front, the top, and the rear side are shown. All width, height and depth measures are rounded to the nearest millimeter.
The E-PM2 can be obtained in four different colors (black, silver, red, 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 (159 percent) than the Olympus E-PM2. Moreover, the 645D is substantially heavier (450 percent) than the E-PM2. It is noteworthy in this context that the 645D is splash and dust-proof, while the E-PM2 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, 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.
|Olympus E-PM2||4.3 in||2.5 in||1.3 in||9.5 oz||360||n||Sep 2012||499|
|Pentax 645D||6.1 in||4.6 in||4.7 in||52.2 oz||800||Y||Mar 2010||9,995|
|Canon 1D X||6.2 in||6.6 in||3.3 in||54.7 oz||1120||Y||Oct 2011||6,799|
|Canon 1D Mark IV||6.1 in||6.2 in||3.1 in||43.4 oz||1500||Y||Oct 2009||4,999|
|Leica S Typ 006||6.3 in||4.7 in||3.1 in||44.4 oz||..||Y||Sep 2012||21,950|
|Nikon D3S||6.3 in||6.2 in||3.5 in||43.7 oz||4200||Y||Oct 2009||5,199|
|Olympus E-PL9||4.6 in||2.7 in||1.5 in||13.4 oz||350||n||Feb 2018||599|
|Olympus E-PL8||4.5 in||2.6 in||1.5 in||12.6 oz||350||n||Sep 2016||549|
|Olympus E-M10 II||4.7 in||3.3 in||1.9 in||13.8 oz||320||n||Aug 2015||649|
|Olympus E-PL7||4.5 in||2.6 in||1.5 in||12.6 oz||350||n||Aug 2014||599|
|Olympus E-P5||4.8 in||2.7 in||1.5 in||14.8 oz||330||n||May 2013||999|
|Olympus E-PL6||4.4 in||2.5 in||1.5 in||11.5 oz||360||n||May 2013||599|
|Olympus E-PL5||4.4 in||2.5 in||1.5 in||11.5 oz||360||n||Sep 2012||599|
|Olympus E-PL3||4.3 in||2.5 in||1.5 in||11.0 oz||300||n||Jun 2011||599|
|Olympus E-PM1||4.3 in||2.5 in||1.3 in||9.3 oz||330||n||Jun 2011||499|
|Panasonic GX850||4.2 in||2.6 in||1.3 in||9.5 oz||210||n||Jan 2017||549|
|Pentax 645Z||6.1 in||4.6 in||4.8 in||54.7 oz||650||Y||Apr 2014||8,499|
Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
(1) Number of images that can be taken on a full battery charge according to the CIPA-standard; (2) Official announcement.
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 E-PM2 was launched at a markedly lower price (by 95 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 Olympus E-PM2 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-PM2 (15.9MP), but the 645D nevertheless has larger individual pixels (pixel pitch of 6.06μm versus 3.76μm for the E-PM2) due to its larger sensor. However, the E-PM2 is a much more recent model (by 2 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 Olympus E-PM2 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 PEN E-PM2 has a native sensitivity range from ISO 100 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 has a markedly higher DXO score than the E-PM2 (overall score 10 points higher), which will translate into better image quality. The advantage is based on 1.9 bits higher color depth, 0.4 EV in additional dynamic range, and 0.4 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.
|Olympus E-PM2||Four Thirds||15.9||4608||3456||1080/30p||22.7||12.2||932||72|
|Pentax 645D||Medium Format||39.5||7264||5440||none||24.6||12.6||1262||82|
|Canon 1D X||Full Frame||17.9||5184||3456||1080/30p||23.8||11.8||2786||82|
|Canon 1D Mark IV||APS-H||16.0||4896||3264||1080/30p||22.8||12.0||1320||74|
|Leica S Typ 006||Medium Format||37.5||7500||5000||none||23.9||12.2||824||76|
|Nikon D3S||Full Frame||12.1||4256||2832||720/24p||23.5||12.0||3253||82|
|Olympus E-PL9||Four Thirds||15.9||4608||3456||4K/30p||..||..||..||..|
|Olympus E-PL8||Four Thirds||15.9||4608||3456||1080/30p||..||..||..||..|
|Olympus E-M10 II||Four Thirds||15.9||4608||3456||1080/60p||23.1||12.5||842||73|
|Olympus E-PL7||Four Thirds||15.9||4608||3456||1080/30p||22.7||12.4||873||72|
|Olympus E-P5||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.4||895||72|
|Olympus E-PL6||Four Thirds||15.9||4608||3456||1080/30p||..||..||..||..|
|Olympus E-PL5||Four Thirds||15.9||4608||3456||1080/30p||22.8||12.3||889||72|
|Olympus E-PL3||Four Thirds||12.2||4032||3024||1080/60i||20.9||10.3||499||52|
|Olympus E-PM1||Four Thirds||12.2||4032||3024||1080/60i||21.0||10.3||499||52|
|Panasonic GX850||Four Thirds||15.8||4592||3448||4K/30p||23.2||13.3||586||73|
|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 E-PM2 indeed provides movie recording capabilities, while the 645D does not. The highest resolution format that the E-PM2 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 E-PM2 relies on live view and the rear LCD for framing. That said, the E-PM2 can be equipped with an optional viewfinder – the VF-4. The table below summarizes some of the other core capabilities of the Olympus E-PM2 and Pentax 645D in connection with corresponding information for a sample of similar cameras.
|Canon 1D X||optical||Y||3.2||1040||fixed||n||1/8000s||14.0||n||n|
|Canon 1D Mark IV||optical||Y||3.0||920||fixed||n||1/8000s||10.0||n||n|
|Leica S Typ 006||optical||Y||3.0||922||fixed||n||1/4000s||1.5||n||n|
|Olympus E-M10 II||2360||n||3.0||1040||tilting||Y||1/4000s||8.0||Y||Y|
One feature that differentiates the E-PM2 and the 645D is in-body image stabilization (IBIS). The E-PM2 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-PM2 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-PM2 only has one slot. The E-PM2 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 PEN E-PM2 and Pentax 645D and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
|Canon 1D X||Y||mono||-||Y||-||mini||2.0||-||-||-|
|Canon 1D Mark IV||Y||stereo||-||Y||-||mini||2.0||-||-||-|
|Leica S Typ 006||Y||-||-||-||-||mini||2.0||-||-||-|
|Olympus E-M10 II||Y||stereo||mono||-||-||micro||2.0||Y||-||-|
Studio photographers will appreciate that the Pentax 645D (unlike the E-PM2) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the E-PM2 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-PM2 does not have a direct successor. 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 how do things add up? Is there a clear favorite between the Olympus E-PM2 and the Pentax 645D? Which camera is better? The listing below highlights the relative strengths of the two models.
Advantages of the Olympus PEN E-PM2:
- 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.
- Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
- Faster burst: Shoots at higher frequency (8 vs 1.1 flaps/sec) to capture the decisive moment.
- More compact: Is smaller (110x64mm vs 156x117mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 1211g or 82 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 (95 percent cheaper at launch).
- More modern: Reflects 2 years and 6 months of technical progress since the 645D launch.
Reasons to prefer 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 markedly higher (10 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (1.9 bits more color depth).
- Better low-light sensitivity: Can shoot in dim conditions (0.4 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.
- More detailed LCD: Has a higher resolution rear screen (921k vs 460k 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 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 645D emerges as the winner of the match-up (14 : 11 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 Olympus E-PM2 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 E-PM2 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 (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.
|Olympus E-PM2||..||77/100||5/5||4.5/5||4.5/5||Sep 2012||499|
|Pentax 645D||..||..||..||4.5/5||..||Mar 2010||9,995|
|Canon 1D X||..||..||4.5/5||4.5/5||4.5/5||Oct 2011||6,799|
|Canon 1D Mark IV||..||89/100||..||5/5||..||Oct 2009||4,999|
|Leica S Typ 006||..||..||..||..||..||Sep 2012||21,950|
|Nikon D3S||..||89/100||4.5/5||5/5||5/5||Oct 2009||5,199|
|Olympus E-PL9||+||..||4.5/5||4.5/5||4/5||Feb 2018||599|
|Olympus E-PL8||..||..||4.5/5||..||4/5||Sep 2016||549|
|Olympus E-M10 II||+ +||80/100||5/5||5/5||5/5||Aug 2015||649|
|Olympus E-PL7||+||..||5/5||4.5/5||4/5||Aug 2014||599|
|Olympus E-P5||+ +||78/100||4.5/5||4.5/5||5/5||May 2013||999|
|Olympus E-PL6||..||..||..||..||..||May 2013||599|
|Olympus E-PL5||+ +||..||4.5/5||4.5/5||4.5/5||Sep 2012||599|
|Olympus E-PL3||+ +||72/100||4.5/5||..||4/5||Jun 2011||599|
|Olympus E-PM1||86/100||71/100||4.5/5||..||4.5/5||Jun 2011||499|
|Panasonic GX850||+||76/100||4.5/5||4/5||4.5/5||Jan 2017||549|
|Pentax 645Z||..||..||4.5/5||5/5||5/5||Apr 2014||8,499|
|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 comparisons of ratings among very different cameras or across long time periods 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.
- Canon XC10 vs Olympus E-PM2
- Nikon B700 vs Olympus E-PM2
- Nikon Coolpix A vs Pentax 645D
- Olympus E-PM2 vs Panasonic GF7
- Olympus E-PM2 vs Panasonic GX85
- Olympus E-PM2 vs Panasonic ZS80
- Olympus E-PM2 vs Sony A6400
- Olympus E-PM2 vs Sony A900
- Olympus E-PM2 vs Sony WX800
- Panasonic GF2 vs Pentax 645D
- Panasonic GX80 vs Pentax 645D
- Pentax 645D vs Sony NEX-F3
Specifications: Olympus E-PM2 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||Olympus E-PM2||Pentax 645D|
|Camera Type||Mirrorless system camera||Digital single lens reflex|
|Camera Lens||Micro Four Thirds lenses||Pentax 645 mount lenses|
|Launch Date||September 2012||March 2010|
|Launch Price||USD 499||USD 9,995|
|Sensor Specs||Olympus E-PM2||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||1080/30p Video||no Video|
|ISO Setting||100 - 25,600 ISO||100 - 1,600 ISO|
|Image Processor||TruePic VI||PRIME II|
|DXO Sensor Quality (score)||72||82|
|DXO Color Depth (bits)||22.7||24.6|
|DXO Dynamic Range (EV)||12.2||12.6|
|DXO Low Light (ISO)||932||1262|
|Screen Specs||Olympus E-PM2||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||460k dots||921k dots|
|LCD Attachment||Fixed screen||Fixed screen|
|Touch Input||Touchscreen||no Touchscreen|
|Shooting Specs||Olympus E-PM2||Pentax 645D|
|Focus System||Contrast-detect AF||Phase-detect AF|
|Continuous Shooting||8 shutter flaps/s||1.1 shutter flaps/s|
|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-PM2||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-PM2||Pentax 645D|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||360 shots per charge||800 shots per charge|
110 x 64 x 34 mm
(4.3 x 2.5 x 1.3 in)
156 x 117 x 119 mm
(6.1 x 4.6 x 4.7 in)
|Camera Weight||269 g (9.5 oz)||1480 g (52.2 oz)|
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