Pentax 645Z vs Sony A7 II
The Pentax 645Z and the Sony Alpha A7 II are two digital cameras that were officially introduced, respectively, in April 2014 and November 2014. The 645Z is a DSLR, while the A7 II is a mirrorless interchangeable lens camera. The cameras are based on a medium format (645Z) and a full frame (A7 II) sensor. The Pentax has a resolution of 51.1 megapixels, whereas the Sony provides 24 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 Pentax 645Z and the Sony Alpha A7 II? 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 Pentax 645Z and the Sony A7 II are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear 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 Sony A7 II is considerably smaller (33 percent) than the Pentax 645Z. Moreover, the A7 II is substantially lighter (61 percent) than the 645Z. 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.
Concerning battery life, the 645Z gets 650 shots out of its D-LI90 battery, while the A7 II can take 350 images on a single charge of its NP-FW50 power pack. The power pack in the A7 II can be charged via the USB port, which can be very convenient when travelling.
The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. If you want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.
|1.||Pentax 645Z||156 mm||117 mm||123 mm||1550 g||650||Y||Apr 2014||8,499|
|2.||Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|3.||Canon 1D X Mark II||158 mm||168 mm||83 mm||1530 g||1210||Y||Feb 2016||5,999|
|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.||Hasselblad X1D||150 mm||98 mm||71 mm||725 g||..||Y||Jun 2016||8,995|
|7.||Leica SL||147 mm||104 mm||39 mm||847 g||400||Y||Oct 2015||7,450|
|8.||Nikon D850||146 mm||124 mm||79 mm||1005 g||1840||Y||Jul 2017||3,299|
|9.||Nikon D5||160 mm||159 mm||92 mm||1415 g||3780||Y||Jan 2016||6,499|
|10.||Nikon D7200||136 mm||107 mm||76 mm||765 g||1110||Y||Mar 2015||1,199|
|11.||Nikon D4S||160 mm||157 mm||91 mm||1350 g||3020||Y||Feb 2014||6,499|
|12.||Pentax 645D||156 mm||117 mm||119 mm||1480 g||800||Y||Mar 2010||9,995|
|13.||Sony A7C||124 mm||71 mm||60 mm||509 g||740||Y||Sep 2020||1,799|
|14.||Sony A9 II||129 mm||96 mm||76 mm||678 g||690||Y||Oct 2019||4,499|
|15.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|16.||Sony A7||127 mm||94 mm||48 mm||474 g||340||Y||Oct 2013||1,699|
|17.||Sony A7R||127 mm||94 mm||48 mm||465 g||340||Y||Oct 2013||2,299|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
The price is, of course, an important factor in any camera decision. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The A7 II was launched at a markedly lower price (by 76 percent) than the 645Z, 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.
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. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better 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 Pentax 645Z features a medium format sensor and the Sony A7 II a full frame sensor. The sensor area in the A7 II is 40 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 0.79 and 1.0. The sensor in the 645Z has a native 4:3 aspect ratio, while the one in the A7 II offers a 3:2 aspect.
In terms of underlying technology, both cameras are build around CMOS sensors.
With 51.1MP, the 645Z offers a higher resolution than the A7 II (24MP), but the 645Z has smaller individual pixels (pixel pitch of 5.30μm versus 5.97μm for the A7 II). Moreover, the A7 II is a somewhat more recent model (by 7 months) than the 645Z, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels. 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 Sony A7 II 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 A7 II has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
The Pentax 645Z has a native sensitivity range from ISO 100 to ISO 204800. The corresponding ISO settings for the Sony Alpha A7 II are ISO 100 to ISO 25600, with the possibility to increase the ISO range to 50-51200.
Consistent information on actual sensor performance is available from DXO Mark for many cameras. This service assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. Of the two cameras under review, the 645Z provides substantially higher image quality than the A7 II, with an overall score that is 11 points higher. This advantage is based on 1.1 bits higher color depth, 1.1 EV in additional dynamic range, and 0.9 stops in additional low light sensitivity. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.
| DXO |
|1.||Pentax 645Z||Medium Format||51.1||8256||6192||1080/60i||26.0||14.7||4505||101|
|2.||Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|3.||Canon 1D X Mark II||Full Frame||20.0||5472||3648||4K/60p||24.1||13.5||3207||88|
|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|
|6.||Hasselblad X1D||Medium Format||51.3||8272||6200||1080/25p||26.2||14.8||4489||102|
|7.||Leica SL||Full Frame||24.0||6000||4000||4K/30p||25.0||13.4||1821||88|
|8.||Nikon D850||Full Frame||45.4||8256||5504||4K/30p||26.4||14.8||2660||100|
|9.||Nikon D5||Full Frame||20.7||5588||3712||4K/30p||25.1||12.3||2343||88|
|11.||Nikon D4S||Full Frame||16.2||4928||3280||1080/60p||24.4||13.3||3074||89|
|12.||Pentax 645D||Medium Format||39.5||7264||5440||none||24.6||12.6||1262||82|
|13.||Sony A7C||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3407||95|
|14.||Sony A9 II||Full Frame||24.0||6000||4000||4K/30p||25.0||14.0||3434||93|
|15.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|16.||Sony A7||Full Frame||24.0||6000||4000||1080/60p||24.8||14.2||2248||90|
|17.||Sony A7R||Full Frame||36.2||7360||4912||1080/60p||25.6||14.1||2746||95|
Many modern cameras are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A7 II provides a faster frame rate than the 645Z. It can shoot movie footage at 1080/60p, while the Pentax is limited to 1080/60i.
Beyond body and sensor, cameras can and do differ across a range of features. For example, the A7 II has an electronic viewfinder (2400k dots), while the 645Z 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 A7 II offers a wider field of view (100%) than the one in the 645Z (98%), so that a larger proportion of the captured image is visible in the finder. On the other hand, the viewfinder of the 645Z 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 adjacent table lists some of the other core features of the Pentax 645Z and Sony A7 II along with similar information for a selection of comparators.
|2.||Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
|3.||Canon 1D X Mark II||optical||Y||3.2||1620||fixed||Y||1/8000s||16.0||n||n|
|5.||Canon 5DS R||optical||Y||3.2||1040||fixed||n||1/8000s||5.0||n||n|
|14.||Sony A9 II||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|15.||Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
One feature that is present on the 645Z, but is missing on the A7 II is a top-level LCD. While being, of course, smaller than the rear screen, the control panel conveys some of the essential shooting information and can be convenient for quick and easy settings verification.
The Pentax 645Z 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 645Z writes its imaging data to SDXC cards, while the A7 II uses SDXC or Memory Stick PRO Duo cards. The 645Z features dual card slots, which can be very useful in case a memory card fails. In contrast, the A7 II 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 Pentax 645Z and Sony Alpha A7 II and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|2.||Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|3.||Canon 1D X Mark II||Y||mono||mono||Y||Y||mini||3.0||-||-||-|
|5.||Canon 5DS R||Y||mono||mono||Y||-||mini||3.0||-||-||-|
|14.||Sony A9 II||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|15.||Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
It is notable that the A7 II offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the 645Z does not provide wifi capability.
Studio photographers will appreciate that the Pentax 645Z (unlike the A7 II) 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 A7 II has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the A7 II was succeeded by the Sony A7 III. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Pentax and Sony websites.
So what is the bottom line? Is the Pentax 645Z better than the Sony A7 II or vice versa? Below is a summary of the relative strengths of each of the two contestants.
Advantages of the Pentax 645Z:
- More detail: Offers more megapixels (51.1 vs 24MP) with a 43% higher linear resolution.
- 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 assessment.
- Richer colors: Generates images with noticeably better colors (1.1 bits more color depth).
- More dynamic range: Captures a larger spectrum of light and dark details (1.1 EV of extra DR).
- Better low-light sensitivity: Requires less light for good images (0.9 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 0.71x).
- Easier setting verification: Features an LCD display on top to control shooting parameters.
- Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Longer lasting: Can take more shots (650 versus 350) on a single battery charge.
- 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).
Arguments in favor of the Sony Alpha A7 II:
- 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).
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- 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 detailed LCD: Has a higher resolution rear screen (1230k vs 1037k dots).
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (5 vs 3 flaps/sec) to capture the decisive moment.
- More compact: Is smaller (127x96mm vs 156x117mm) and will fit more readily into a bag.
- Less heavy: Has a lower weight (by 951g or 61 percent) and is thus easier to take along.
- Easier travel charging: Can be conveniently charged via its USB port.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- More legacy lens friendly: Can use many non-native lenses via adapters.
- 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 into a lower priced category (76 percent cheaper at launch).
- More modern: Was introduced somewhat (7 months) more recently.
If the count of individual advantages (bullet points above) is taken as a guide, the A7 II emerges as the winner of the match-up (18 : 16 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 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 Pentax 645Z and the Sony A7 II place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Mirrorless Interchangeable Lens 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 645Z and the A7 II in practical situations. 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 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.||Pentax 645Z||5/5||..||..||4.5/5||5/5||Apr 2014||8,499|
|2.||Sony A7 II||5/5||+||82/100||4.5/5||5/5||Nov 2014||1,999|
|3.||Canon 1D X Mark II||..||..||89/100||4.5/5||4.5/5||Feb 2016||5,999|
|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.||Hasselblad X1D||..||o||81/100||..||4/5||Jun 2016||8,995|
|7.||Leica SL||4/5||..||84/100||4.5/5||4/5||Oct 2015||7,450|
|8.||Nikon D850||4.5/5||+ +||89/100||4.5/5||5/5||Jul 2017||3,299|
|9.||Nikon D5||..||..||89/100||4.5/5||5/5||Jan 2016||6,499|
|10.||Nikon D7200||4/5||+ +||84/100||4.5/5||4.5/5||Mar 2015||1,199|
|11.||Nikon D4S||5/5||..||..||4.5/5||4.5/5||Feb 2014||6,499|
|12.||Pentax 645D||5/5||..||..||..||..||Mar 2010||9,995|
|13.||Sony A7C||3.5/5||..||86/100||4/5||4/5||Sep 2020||1,799|
|14.||Sony A9 II||..||..||90/100||5/5||5/5||Oct 2019||4,499|
|15.||Sony A7 III||..||+ +||89/100||5/5||5/5||Feb 2018||1,999|
|16.||Sony A7||5/5||+ +||80/100||5/5||5/5||Oct 2013||1,699|
|17.||Sony A7R||5/5||+ +||82/100||4.5/5||5/5||Oct 2013||2,299|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
Care should be taken when interpreting the review scores above, 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 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 would like to check on the differences and similarities of other camera models, just use the search menu below. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.
Specifications: Pentax 645Z vs Sony A7 II
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||Pentax 645Z||Sony A7 II|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Pentax 645 mount lenses||Sony E mount lenses|
|Launch Date||April 2014||November 2014|
|Launch Price||USD 8,499||USD 1,999|
|Sensor Specs||Pentax 645Z||Sony A7 II|
|Sensor Format||Medium Format Sensor||Full Frame Sensor|
|Sensor Size||43.8 x 32.8 mm||35.8 x 23.9 mm|
|Sensor Area||1436.64 mm2||855.62 mm2|
|Sensor Diagonal||54.7 mm||43 mm|
|Sensor Resolution||51.1 Megapixels||24 Megapixels|
|Image Resolution||8256 x 6192 pixels||6000 x 4000 pixels|
|Pixel Pitch||5.30 μm||5.97 μm|
|Pixel Density||3.56 MP/cm2||2.80 MP/cm2|
|Moiré control||no AA filter||Anti-Alias filter|
|Movie Capability||1080/60i Video||1080/60p Video|
|ISO Setting||100 - 204,800 ISO||100 - 25,600 ISO|
|ISO Boost||no Enhancement||50 - 51,200 ISO|
|Image Processor||PRIME III||BIONZ X|
|DXO Sensor Quality (score)||101||90|
|DXO Color Depth (bits)||26.0||24.9|
|DXO Dynamic Range (EV)||14.7||13.6|
|DXO Low Light (ISO)||4505||2449|
|Screen Specs||Pentax 645Z||Sony A7 II|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||98%||100%|
|Viewfinder Resolution||2400k dots|
|Top-Level Screen||Control Panel||no Top Display|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.2inch||3.0inch|
|LCD Resolution||1037k dots||1230k dots|
|LCD Attachment||Tilting screen||Tilting screen|
|Shooting Specs||Pentax 645Z||Sony A7 II|
|Focus System||Phase-detect AF||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||3 shutter flaps/s||5 shutter flaps/s|
|Shutter Life Expectancy||100 000 actuations||200 000 actuations|
|Time-Lapse Photography||Intervalometer built-in||no Intervalometer|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||no On-Board Flash||no On-Board Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Dual card slots||Single card slot|
|UHS card support||UHS-I||UHS-I|
|Connectivity Specs||Pentax 645Z||Sony A7 II|
|Studio Flash||PC Sync socket||no PC Sync|
|USB Connector||USB 3.0||USB 2.0|
|HDMI Port||mini HDMI||micro HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||no Wifi||Wifi built-in|
|Near-Field Communication||no NFC||NFC built-in|
|Body Specs||Pentax 645Z||Sony A7 II|
|Environmental Sealing||Weathersealed body||Weathersealed body|
|Battery Life (CIPA)||650 shots per charge||350 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
156 x 117 x 123 mm
(6.1 x 4.6 x 4.8 in)
127 x 96 x 60 mm
(5.0 x 3.8 x 2.4 in)
|Camera Weight||1550 g (54.7 oz)||599 g (21.1 oz)|
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