Pentax K-3 vs Sony A7R III

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Pentax K-3 vs Sony A7R III

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APS-C 366.6mm²
24.4 megapixels
ISO 100 - 51,200

Go in depth with our full Pentax K-3 Review.
How does it shoot? Pentax K-3 in the real world.
See real-world photos taken with the K-3.
Compare Pentax K-3 image quality against competitors.
What’s the bottom line? Read our Pentax K-3 conclusion.

35mm 861.6mm²
42.4 megapixels
ISO 100 - 32,000

Go in depth with our full Sony A7R III Review.
How does it shoot? Sony A7R III in the real world.
See real-world photos taken with the A7R III.
Compare Sony A7R III image quality against competitors.
What’s the bottom line? Read our Sony A7R III conclusion.

Succeeded by the Pentax K-3 II
Compare K-3 vs K-3 II

Succeeded by the Sony A7R IV
Compare A7R III vs A7R IV

Compare PENTAX K-3 II vs SONY A7R IV

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Differences

Pentax K-3 advantages over Sony A7R III

Lens selection
Excellent vs Good
Better lens selection gives you more options
Fast startup
~0.90 vs 1.7 sec
Faster startup lets you catch the moment
Internal flash
Internal flash vs None
Useful in a pinch for fill flash
Top deck display
Yes vs No
Check settings with a screen on top of the camera
Less shutter lag
0.14 vs 0.25 sec
Focus and take a photo quickly (wide angle)
Optional anti-aliasing filter
Optional vs None
Lets you choose sharper photos or reduced moiré

Sony A7R III advantages over Pentax K-3

Larger sensor
35mm vs APS-C
More sensor area. Bigger is (generally) better.
Bigger pixels
~ 4.51 vs 3.91 microns
Better low-light and dynamic range (all else equal)
Shoot 4K video
4K (UHD) vs 1080p
Make sure you have a fast computer
Touchscreen
Touch vs No touch
Interact with your camera just like your smartphone
Tiltable Screen
Tiltable vs Fixed
Tilt the screen for shooting flexbility
High resolution composite
Yes vs No
Combine multiple shots to form a super hi-res version
Built-in Wi-Fi
Wi-Fi vs None
Share your photos wirelessly
NFC
Yes vs No
Simplifies pairing your camera with supported phones
Built-in Bluetooth
Yes vs No
Always-on wireless connectivity
Higher effective ISO

Higher effective ISO

Maximum effective ISO is an estimate of the highest sensitivity at which a camera can capture excellent quality photos.

Cameras with higher effective ISO will be better choices for indoor photography, night shooting, and indoor sports photography, especially if you intend to make large prints.

You can learn more at our glossary entry.

Maximum effective ISO test data courtesy of DxO Mark.
A7R III test data on DxO Mark K-3 test data on DxO Mark

3,523 vs 1,216 iso
Take photos in low light with less noise
On-sensor phase detect
Yes vs No
Usually improves live view and video AF performance
Newer
7 years vs 11 years old
Newer cameras often support more advanced features
More viewfinder magnification
0.78x vs 0.63x
Get a bigger view of the scene through the eye-level viewfinder
More pixels
42.4 vs 24.4 megapixels
Higher resolution photos
Faster JPEG shooting
9.9 fps vs 7.1 fps
Faster JPEG shooting (burst mode)
Faster RAW shooting
9.2 fps vs 7.1 fps
Faster RAW shooting in burst mode
Slow-motion videos
Yes vs No
Shoot slow-motion videos
Higher extended ISO
102400 vs 51200 ISO
Higher extended ISO can give more low-light flexibility

Similarities

Common Strengths

Focus peaking
Both provide
Your camera will highlight what's in focus
Eye-level viewfinder
Both provide
You'll be able to frame photos even when the sun is out
In-Camera Image Stabilization
Both provide
Reduces the effects of camera shake at slower shutter speeds
External Mic Jack
Both provide
Improved sound fidelity when shooting video
HDMI out
Both provide
Use HDMI output to monitor or review video
Hot shoe
Both provide
Off-camera flashes open new possibilities
Dual card slots
Both provide
Gives you more storage flexibility
Headphone jack
Both provide
Monitor audio recording while you shoot video
Bulb shutter
Both provide
Hold the shutter open manually for long exposures

Common Weaknesses

Tilt-swivel screen
Neither provide
Tilt and swivel the screen for maximum shooting flexibility
In-camera panoramas
Neither provide
Stitches multiple shots into a panoramic photo
Built-in GPS
Neither provide
Geotag your photos

User reviews

Amazon
Adorama
Read K-3 User Reviews

Amazon
Adorama
Read A7R III User Reviews

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Kit with 18-135mm Lens

All K-3 Deals

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Buy the Sony A7R III

Body Only

Body Only
Kit with 24-70mm f/2.8 GM lens
Kit with 24-70mm f/4 lens

All A7R III Deals

Review Excerpt

Top-notch image quality; Great ergonomics in a compact body; Unique on-demand low-pass filtering; Broad sensitivity range; Large and bright viewfinder for an APS-C camera; Dual card slots; Optional Wi-Fi remote control
AE Lock button is poorly located; Below-average battery life for a DSLR; Rather dated-looking menu system; Requires a different battery grip accessory than its predecessors; Less third-party support than some rivals
Read our Pentax K-3 Review

Fantastic image quality; Improved dynamic range over its predecessor; Very good high ISO performance; Much improved real-world AF performance; Class-leading burst rates, even with RAW; Improved 5-axis in-body image stabilization; Better 4K video quality; 1080/120fps video; Dual card slots; Significantly better battery life.
Expensive; Menus still confusing; UHS-II support only on one card slot; No optical low-pass filter means greater risk of moire; No built-in flash; Buffer clearing still slow despite UHS-II support.
Read our Sony A7R III Review

The Competition

Compared to Nikon D7100

Pentax K-3

Nikon D7100

$699
APS-C

Focus peaking
In-Camera Image Stabilization

$745
APS-C

Fast startup
Longer stills battery life

Compare Pentax K-3 vs Nikon D7100

Sony A7R III

Nikon D7100

$2151
35mm

Focus peaking
Larger sensor

$745
APS-C

Less expensive
Lens selection

Compare Sony A7R III vs Nikon D7100

Compared to Nikon D5300

Pentax K-3

Nikon D5300

$699
APS-C

Focus peaking
In-Camera Image Stabilization

$549
APS-C

Tilt-swivel screen
Fast startup

Compare Pentax K-3 vs Nikon D5300

Sony A7R III

Nikon D5300

$2151
35mm

Focus peaking
Larger sensor

$549
APS-C

Less expensive
Tilt-swivel screen

Compare Sony A7R III vs Nikon D5300

Compared to Nikon D7200

Pentax K-3

Nikon D7200

$699
APS-C

Focus peaking
In-Camera Image Stabilization

$1016
APS-C

Fast startup
Built-in Wi-Fi

Compare Pentax K-3 vs Nikon D7200

Sony A7R III

Nikon D7200

$2151
35mm

Focus peaking
Larger sensor

$1016
APS-C

Less expensive
Lens selection

Compare Sony A7R III vs Nikon D7200

Compared to Sony A7R II

Pentax K-3

Sony A7R II

$699
APS-C

Lens selection
Fast startup

$2348
35mm

Larger sensor
Bigger pixels

Compare Pentax K-3 vs Sony A7R II

Sony A7R III

Sony A7R II

$2151
35mm

Touchscreen
High resolution composite

$2348
35mm

In-camera panoramas

Compare Sony A7R III vs Sony A7R II

Compared to Nikon Z7 II

Pentax K-3

Nikon Z7 II

$699
APS-C

More telephoto lens reach
Internal flash

$2330
35mm

Larger sensor
Shoot 4K video

Compare Pentax K-3 vs Nikon Z7 II

Sony A7R III

Nikon Z7 II

$2151
35mm

Less expensive
High resolution composite

$2330
35mm

Top deck display
Newer

Compare Sony A7R III vs Nikon Z7 II

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