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Pentax 645Z vs Olympus E-M1 II

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Pentax 645Z

51 MP | Medium format (44 x 33 mm) CMOS Sensor

Pentax 645Z
$5,496.95
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Olympus E-M1 II

20 MP | Four Thirds (17.4 x 13 mm) CMOS Sensor

Olympus E-M1 II
$1,999.99
Pentax 645Z vs Olympus E-M1 II Comparison Overview

Here we are comparing two cameras with different body types: Pentax 645Z is a Pro DSLR camera with a 51.0MP Medium format sensor whereas Olympus E-M1 II is a Pro Mirrorless camera with a 20.0MP Four Thirds sensor.
Despite some fundamental differences of these two body types, Mirrorless cameras are becoming serious altenatives to DSLR cameras thanks to their size/weight advantages and recent improvements in their focus speeds , which makes this comparison even more interesting. Fortunately, you can't go wrong with any of these cameras as we rank them amongst Top 10 cameras in their classes. Pentax 645Z is ranked #1 out of 34 Pro DSLR cameras with an overall score of 88 whereas Olympus E-M1 II is ranked #9 out of 30 Pro Mirrorless cameras with an overall score of 89.

Let's have a brief look at the main features of Pentax 645Z and Olympus E-M1 II before getting into our more detailed comparison.

Pentax 645Z Key Specs

  • Announcement Date: 2014-04-15
  • 51MP - Medium format CMOS Sensor
  • No Anti-aliasing (AA) filter
  • ISO 100 - 204800
  • Pentax 645AF2 Mount
  • 3.2″ Tilting Screen
  • Optical (pentaprism) viewfinder
  • 3 fps continuous shooting
  • 1920 x 1080 video resolution
  • 1550g. 156 x 117 x 123 mm
  • Weather Sealed Body
  • Replaced Pentax 645D Compare

Olympus E-M1 II Key Specs

  • Announcement Date: 2016-09-19
  • 20MP - Four Thirds CMOS Sensor
  • ISO 200 - 25600 ( expands to 64)
  • Micro Four Thirds Mount
  • Sensor-shift Image Stabilization
  • 3″ Fully Articulated Screen
  • 2360k dot Electronic viewfinder
  • 15.0 fps continuous shooting
  • 4096 x 2060 video resolution
  • Built-in Wireless
  • 574g. 134 x 91 x 67 mm
  • Weather Sealed Body
  • Replaced Olympus OM-D E-M1 Compare
Reasons to choose Pentax 645Z over Olympus OM-D E-M1 Mark II
Max Sensor Resolution 51 MP vs 20 MP 154% more pixels
Max ISO 204.800 vs 25.600 700% higher Max ISO
LCD Screen Size 3.2″ vs 3″ 0.2 inches larger display
Battery Life 650 shots vs 350 shots 300 more frames with a single charge
Color Depth 26.0 vs 23.7 higher color depth
Dynamic Range 14.7 vs 12.8 higher dynamic range
Low Light ISO 4505 vs 1312 better High ISO performance
Sensor Pixel Area 28.40µm2 vs 11.22µm2 153% larger pixel area
Top LCD Yes vs No Help viewing and changing settings easily
Reasons to choose Olympus OM-D E-M1 Mark II over Pentax 645Z
Wireless Connection Built-In vs None Better connectivity
Built-in Image Stabilization Sensor-shift vs None All the lenses are stabilized
Touch Screen Yes vs No Easy control of camera functions
Number of Focus Points 121 vs 27 94 more focus points
Viewfinder Coverage 100% vs 98% More accurate viewfinder
Max Shutter Speed 1/8000s vs 1/4000s faster shutter speed
Continuous Shooting 15.0fps vs 3.0fps 12 fps faster
Weight 574 g vs 1550 g 976 g lighter
Headphone Port Yes vs No better video control
Price $2,000 vs $5,497 $3,497 cheaper
Max Video Resolution 4096 x 2060 vs 1920 x 1080 Higher Resolution Video
Flash Sync Port Yes vs No Connect off-camera flash
Pixel Shift High Resolution Mode Yes (50.0MP) vs No Increased resolution with pixel shift
Focus Bracketing Yes vs No Take multiple photos shifting focus point
Focus Stacking Yes vs No Stacks photos in-camera to maximize depth of field
Smartphone_remote control Yes vs No Remote control your camera with a smartphone
Support for UHS Memory Cards UHS-II vs none Read/Write in Ultra High Speeds
Common Strengths of Pentax 645Z and Olympus OM-D E-M1 Mark II
Articulating Screen Yes vs Yes Flexible shooting positions
External Flash Shoe Yes vs Yes Better for flash photography
Viewfinder Yes (Optical) vs Yes (Electronic) Better framing and control
RAW Support Yes vs Yes Better image quality
Face Detection Focus Yes vs Yes very handy for portraits
Max Resolution 51 MP vs 20 MP Bigger prints and more details
LCD Screen Resolution 1.037k dots vs 1.037k dots Higher resolution screens
Microphone Port Yes vs Yes High quality audio recording option
Environmental Sealing Yes vs Yes shoot at tough conditions
Timelapse Recording Yes vs Yes creative shooting
AE Bracketing Yes vs Yes Useful for tough lighting conditions and HDR
Storage Slot 2 vs 2 Extra Storage Slot
Common Weaknesses of Pentax 645Z and Olympus OM-D E-M1 Mark II
Built-in Flash No vs No Require external flash
Pentax 645Z vs Olympus E-M1 II: Physical Specs Comparison

Below you can see the front view size comparison of Pentax 645Z and Olympus E-M1 II. Olympus E-M1 II is clearly the smaller of the two cameras. Its body is 22mm narrower, 26mm shorter and 56mm thinner than Pentax 645Z.

Pentax 645Z vs Olympus E-M1 II Camera Size Comparison - Front View
Now lets look at the top view comparison of Pentax 645Z and Olympus E-M1 II.
Pentax 645Z vs Olympus E-M1 II Camera Size Comparison - Top View

Pentax 645Z vs Olympus E-M1 II Detailed Size Comparison

Weight is another important factor especially when deciding on a camera that you want to carry with you all day. Olympus E-M1 II is significantly lighter (976g ) than the Pentax 645Z which may become a big advantage especially on long walking trips.

Also keep in mind that body weight is not the only deciding factor when comparing two interchangeable camera bodies, you have to also take into account the lenses that you will be using with these bodies. Since Pentax 645Z has a Medium format sensor and Olympus E-M1 II has a smaller Four Thirds sensor, Olympus E-M1 II's lenses for a similar focal length and aperture will generally be lighter and smaller than the Pentax 645Z lenses.

Weight Comparison

Mirrorless Cameras

645Z
E-M1 II
Min
Average
Max
Thickness Comparison

Mirrorless Cameras

645Z
E-M1 II
Min
Average
Max
Pentax 645Z vs Olympus E-M1 II: Sensor Comparison

Pentax 645Z has a 51.0MP Medium format (44 x 33 mm ) sized CMOS sensor and features PRIME III processor. On the other hand, Olympus E-M1 II has a 20.0MP Four Thirds (17.4 x 13 mm ) sized CMOS sensor and features TruePic VIII processor.

Pentax 645Z's sensor provides 31MP more than Olympus E-M1 II's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely. On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.

Another difference between these two cameras is that Pentax 645Z's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moire occurring in certain scenes.

Below you can see the 645Z and E-M1 II sensor size comparison.

Pentax 645Z vs Olympus E-M1 II Sensor Size Comparison


As seen above, Pentax 645Z has a 6.4x Larger sensor area than Olympus E-M1 II. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.

What types of Photography are Pentax 645Z and Olympus E-M1 II Good for?
In this section, we rank and compare Pentax 645Z and Olympus E-M1 II for five different photography types in order to make your decision process easier in case you are specifically interested in one or more of these areas.

Pentax 645Z for Portrait Photography

EXCELLENT

Olympus E-M1 II for Portrait Photography

GOOD
Large Medium format (44 x 33 mm) sensor
Very High Resolution Sensor: 51.0MP
Optical Built-in Viewfinder
Good Ergonomics&Handling
No Image Stabilization
Read the details
Large Four Thirds (17.4 x 13 mm) sensor
Very High Resolution Sensor: 20.0MP
Image Stabilization
Electronic Built-in Viewfinder
Good Ergonomics&Handling
Read the details

Pentax 645Z for Street Photography

GOOD

Olympus E-M1 II for Street Photography

EXCELLENT
Large Medium format (44 x 33 mm) sensor
Optical Built-in Viewfinder
Live-view
Face-Detection Focusing
Tilting LCD Screen
No Image Stabilization
Large Body
Read the details
Large Four Thirds (17.4 x 13 mm) sensor
Image Stabilization
Electronic Built-in Viewfinder
Live-view
Face-Detection Focusing
Fully Articulated LCD Screen
Medium sized Body
Read the details

Pentax 645Z for Sports Photography

GOOD

Olympus E-M1 II for Sports Photography

EXCELLENT
Optical Built-in Viewfinder
Good Ergonomics&Handling
Environmental Sealings
Fast Max shutter speed: 1/4000s
27 Focus Points
Good Battery Life: 650 shots
Good Low Light ISO
No Image Stabilization
Slow Continuous Shooting: 3.0fps
Read the details
Image Stabilization
Electronic Built-in Viewfinder
Good Ergonomics&Handling
Fast Continuous Shooting: 15.0fps
Environmental Sealings
Fast Max shutter speed: 1/8000s
121 Focus Points
Good Low Light ISO
Wireless Connection
Read the details

Pentax 645Z for Daily Photography

EXCELLENT

Olympus E-M1 II for Daily Photography

GOOD
Large Medium format (44 x 33 mm) sensor
Environmental Sealings
Large Body
1550g
Body Thickness 123mm
Read the details
Large Four Thirds (17.4 x 13 mm) sensor
Environmental Sealings
Medium size Body
574g
Body Thickness 67mm
Read the details

Pentax 645Z for Landscape Photography

EXCELLENT

Olympus E-M1 II for Landscape Photography

AVERAGE
Large Medium format (44 x 33 mm) sensor
Very High Resolution Sensor: 51.0MP
Environmental Sealings
Live-view
Read the details
Large Four Thirds (17.4 x 13 mm) sensor
Very High Resolution Sensor: 20.0MP
Environmental Sealings
Live-view
Read the details


Olympus E-M1 II vs Pentax 645Z Comparison of Available Lenses
Which camera has more lenses?

Number of available lenses is a big decision factor while choosing your interchangeable lens camera. When we look at the available lenses for these two cameras, we see that Olympus E-M1 II has an advantage over Pentax 645Z There are 92 lenses for Olympus E-M1 II's Micro Four Thirds mount, on the other hand there are only 6 lenses for Pentax 645Z's Pentax 645AF2 lens mount.

Another important factor is the availability of image stabilization. Olympus E-M1 II has a big advantage in this regard because it has a sensor based image stabilization which means that all the lenses mounted to this body will be stabilized. On the other hand, Pentax 645Z doesn't have this feature so you have to buy a lens with optical stabilization feature. Currently there are 2 lenses for Pentax 645AF2 mount with Optical Image Stabilization features.

Lens Type # of Pentax 645Z Lenses # of Olympus E-M1 II Lenses
Standard Zoom 1 14
Standard Prime 1 11
Wideangle Zoom 1 4
Wideangle Prime 1 23
Telephoto Zoom n/a 16
Telephoto Prime n/a 8
SuperZoom n/a 6
Wideangle Fisheye Prime n/a 5
Macro Prime 1 4
Perspective Control Prime n/a n/a
Telephoto Mirror Prime n/a 1
TOTAL 6 92
Pentax 645Z vs Olympus E-M1 II: OUR DECISION

You may have already made your decision about which camera suits better for your needs and your budget so far but in case you wonder how we rated Pentax 645Z and Olympus E-M1 II, below you can find their scores in five different aspects. Our Decision Algorithm dynamically scores cameras using 63 different specs, current price and DxO Mark scores (where possible) in order to make a more objective and consistent comparison.

Here is a summary of how Pentax 645Z and Olympus E-M1 II scores compare:

Pentax 645Z
Imaging
Features
Value
Portability
Overall
Ranked #1 out of 10 in Large SLR cameras
Ranked #18 out of 1131 in all Cameras
Olympus E-M1 II
Imaging
Features
Value
Portability
Overall
Ranked #6 out of 49 in SLR-style mirrorless cameras
Ranked #15 out of 1131 in all Cameras

Olympus E-M1 II has a higher Overall Score than the Pentax 645Z and would be our choice if we have to decide between these two cameras.

Pentax 645Z
Pentax 645Z
$5,496.95

Olympus E-M1 II
Olympus E-M1 II
$1,999.99

Olympus E-M1 II vs Pentax 645Z Specs Table
Detailed comparison of specifications
General Pentax 645Z Olympus OM-D E-M1 Mark II
Brand Pentax Olympus
Announced 2014-04-15 2016-09-19
Body Type Large SLR SLR-style mirrorless
Price $5,496.95 $1,999.99
Sensor
Type CMOS CMOS
Size Medium format Four Thirds
Dimensions 44 x 33 mm 17.4 x 13 mm
Area 1452.00mm2 226.20mm2
Megapixels 51 megapixels 20 megapixels
Max Resolution 8256 x 6192 5184 x 3888
Max Native Light sensitivity 204,800 ISO 25,600 ISO
Min Native Light sensitivity 100 ISO 200 ISO
Min Boosted Light Sensitivity - 64 ISO
RAW Support
Autofocus
AF Touch
AF Continuous
AF Single
AF Tracking
AF Selective
AF Center
AF Multi Area
AF Live View
AF Face Detection
AF Contrast Detection
AF Phase Detection
Number of Focus Points 27 121
Lens
Manual Focus
Lens Mount Pentax 645AF2 Micro Four Thirds
Number of Available Lenses 6 92
Screen
Type Tilting Fully Articulated
Size 3.2″ 3″
Resolution 1,037k dots 1,037k dots
Touch Screen
Viewfinder
Viewfinder Optical (pentaprism) Electronic
Viewfinder Resolution no electronic viewfinder 2,360k dots
Viewfinder Coverage 98% 100%
Viewfinder Magnification 0.85 n/a
Photography Features
Max Shutter Speed 1/4000s 1/8000s
Shutter Priority
Aperture Priority
Manual Exposure Mode
Custom White Balance
Image Stabilization No Sensor-shift
Built-in Flash
Flash Range no built-in flash 9.10 m (at ISO 100)
External Flash
Continuous Shooting 3.0 fps 15.0 fps
Multi-Segment
Average
Spot
Partial
AF-Area
Center Weighted
AE Bracketing
WB Bracketing
Video Features
Max Video Resolution 1920 x 1080 4096 x 2060
Video Formats MPEG-4, H.264 MOV, H.264
Microphone Port
Headphone Port
Connectivity
Wireless Connectivity None Built-In
HDMI
Physical
Environmental Sealing
Weight 1550g 574g
Dimensions 156 x 117 x 123mm 134 x 91 x 67mm
Battery Life 650 shots 350 shots
Other Features
Timelapse Recording
GPS Optional None
DxO Sensor Scores
DxO Overall Score 101 80
DxO Color Depth 26.0 23.7
DxO Dynamic Range 14.7 12.8
DxO Low Light ISO 4505 1312
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