Pentax K-x vs Sony RX100 III

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Pentax K-x vs Sony RX100 III

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APS-C 369.7mm²
12.4 megapixels
ISO 200 - 6400

Go in depth with our full Pentax K-x Review.
See real-world photos taken with the K-x.

1 inch 116.2mm²
20.2 megapixels
24.00mm - 70.00mm (35mm eq.)

Go in depth with our full Sony RX100 III Review.
How does it shoot? Sony RX100 III in the real world.
See real-world photos taken with the RX100 III.
Compare Sony RX100 III image quality against competitors.
What’s the bottom line? Read our Sony RX100 III conclusion.

Succeeded by the Pentax K-r
Compare K-x vs K-r

Succeeded by the Sony RX100 IV
Compare RX100 III vs RX100 IV

Compare PENTAX K-R vs SONY RX100 IV

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Differences

Pentax K-x advantages over Sony RX100 III

Larger sensor
APS-C vs 1 inch
More sensor area. Bigger is (generally) better.
Bigger pixels
~ 5.53 vs 2.41 microns
Better low-light and dynamic range (all else equal)
Fast startup
~0.60 vs 2.0 sec
Faster startup lets you catch the moment
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.
K-x test data on DxO Mark RX100 III test data on DxO Mark

811 vs 495 iso
Take photos in low light with less noise
Longer stills battery life
More info

Longer stills battery life

Cameras with longer battery life can take more photos before exhausting their batteries.

Special note: The measurement standard for battery life stipulates that if a camera has an internal flash, it must be used for 50% of photos taken. For this reason, comparisons of one camera with an internal flash to another without will not be comparable

420 vs 320 shots
Capture more photos
Hot shoe
Hot shoe vs None
Off-camera flashes open new possibilities
Faster shutter
1/6000 vs 1/2000 sec
Shoot wide open in bright light

Sony RX100 III advantages over Pentax K-x

Focus peaking
Peaker vs Non-peaker
Your camera will highlight what's in focus
In-camera panoramas
Yes vs No
Stitches multiple shots into a panoramic photo
Tiltable Screen
Tiltable vs Fixed
Tilt the screen for shooting flexbility
Built-in Wi-Fi
Wi-Fi vs None
Share your photos wirelessly
NFC
Yes vs No
Simplifies pairing your camera with supported phones
Integrated ND filter
Yes vs No
Shoot in daylight with a large aperture or slow shutter
Thinner
41 mm vs 69 mm
Thinner
Higher max flash sync
1/2000 vs 1/180 sec
Reduce the effect of ambient light in flash shots
Newer
10 years vs 15 years old
Newer cameras often support more advanced features
HDMI out
HDMI out vs None
Use HDMI output to monitor or review video
More dots on screen
1229k vs 230k dots
Can mean greater resolution or a brighter screen
Shoots 1080p video
Yes vs No
You'll want this if you shoot video
More pixels
20.2 vs 12.4 megapixels
Higher resolution photos
Shoots 60p video
Yes vs No
A faster framerate can give you more editing options
Faster JPEG shooting
10.0 fps vs 4.3 fps
Faster JPEG shooting (burst mode)
Bigger JPEG buffer
48 vs 25 shots
Take more JPEG shots before waiting (burst mode)
Slow-motion videos
Yes vs No
Shoot slow-motion videos
Higher extended ISO
25600 vs 12800 ISO
Higher extended ISO can give more low-light flexibility

Similarities

Common Strengths

Rear display
Both provide
Review photos on the back of the camera
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
RAW file ability
Both provide
Gives you more flexibility to develop your photos later
Internal flash
Both provide
Useful in a pinch for fill flash
Manual focus
Both provide
AF is for the weak. Real photographers focus manually.
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
Touchscreen
Neither provide
Interact with your camera just like your smartphone
Built-in Bluetooth
Neither provide
Always-on wireless connectivity
Built-in GPS
Neither provide
Geotag your photos
On-sensor phase detect
Neither provide
Usually improves live view and video AF performance
Top deck display
Neither provide
Check settings with a screen on top of the camera
External Mic Jack
Neither provide
Improved sound fidelity when shooting video
Dual card slots
Neither provide
Gives you more storage flexibility
Headphone jack
Neither provide
Monitor audio recording while you shoot video

User reviews

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Read K-x User Reviews

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Review Excerpt

Read our Pentax K-x Full Review

Pocket-friendly design; Popup electronic viewfinder; Bright lens across the zoom range; Great performance with very fast autofocus; Very high resolution gives lots of detail in good light; High ISO noise levels much better than most pocket camera rivals; Wi-Fi wireless networking
Feels a little unbalanced without an accessory grip; Not as much telephoto reach as its siblings; Noise processing is heavier-handed than in earlier models; Quite pricey for a fixed-lens camera
Read our Sony RX100 III Review

The Competition

Compared to Sony RX100

Pentax K-x

Sony RX100

$702
APS-C

Larger sensor
Eye-level viewfinder

$1074
1 inch

Focus peaking
In-camera panoramas

Compare Pentax K-x vs Sony RX100

Sony RX100 III

Sony RX100

$748
1 inch

Eye-level viewfinder
Tiltable Screen

$1074
1 inch

More telephoto lens reach
Faster RAW shooting

Compare Sony RX100 III vs Sony RX100

Compared to Sony RX100 II

Pentax K-x

Sony RX100 II

$702
APS-C

Larger sensor
Eye-level viewfinder

$598
1 inch

Focus peaking
In-camera panoramas

Compare Pentax K-x vs Sony RX100 II

Sony RX100 III

Sony RX100 II

$748
1 inch

Eye-level viewfinder
Fast startup

$598
1 inch

Less expensive
More telephoto lens reach

Compare Sony RX100 III vs Sony RX100 II

Compared to Canon G7X

Pentax K-x

Canon G7X

$702
APS-C

Larger sensor
Eye-level viewfinder

$1239
1 inch

Focus peaking
Touchscreen

Compare Pentax K-x vs Canon G7X

Sony RX100 III

Canon G7X

$748
1 inch

Eye-level viewfinder
In-camera panoramas

$1239
1 inch

Touchscreen
More telephoto lens reach

Compare Sony RX100 III vs Canon G7X

Compared to Panasonic LX100

Pentax K-x

Panasonic LX100

$702
APS-C

Larger sensor
Bigger pixels

$598
4/3

Focus peaking
Shoot 4K video

Compare Pentax K-x vs Panasonic LX100

Sony RX100 III

Panasonic LX100

$748
1 inch

Tiltable Screen
Internal flash

$598
4/3

Less expensive
Larger sensor

Compare Sony RX100 III vs Panasonic LX100

Compared to Sony DSLR-A380

Pentax K-x

Sony DSLR-A380

$702
APS-C

Lens selection
Less expensive

$849
APS-C

Tiltable Screen
HDMI out

Compare Pentax K-x vs Sony DSLR-A380

Sony RX100 III

Sony DSLR-A380

$748
1 inch

Focus peaking
In-camera panoramas

$849
APS-C

Larger sensor
Bigger pixels

Compare Sony RX100 III vs Sony DSLR-A380

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