Pentax K20D vs Nikon D3100

Cameras
Compare Cameras
Pentax K20D vs Nikon D3100

Leave Feedback

APS-C 368.2mm²
14.6 megapixels
ISO 100 - 3200

Go in depth with our full Pentax K20D Review.
See real-world photos taken with the K20D.

APS-C 355.7mm²
14.2 megapixels
ISO 100 - 3200

Go in depth with our full Nikon D3100 Review.
See real-world photos taken with the D3100.

Succeeded by the Pentax K-7
Compare K20D vs K-7

Succeeded by the Nikon D3200
Compare D3100 vs D3200

Compare PENTAX K-7 vs NIKON D3200

Buy From

Differences

Pentax K20D advantages over Nikon D3100

In-Camera Image Stabilization
Yes vs No
Reduces the effects of camera shake at slower shutter speeds
Top deck display
Yes vs No
Check settings with a screen on top of the camera
More cross-type AF points
9 vs 1
Cross-type AF points improve autofocus performance
Pentaprism viewfinder
Pentaprism vs Pentamirror
Much better viewfinder picture fidelity
Less shutter lag
0.17 vs 0.28 sec
Focus and take a photo quickly (wide angle)
More viewfinder magnification
0.63x vs 0.53x
Get a bigger view of the scene through the eye-level viewfinder

Nikon D3100 advantages over Pentax K20D

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.
D3100 test data on DxO Mark K20D test data on DxO Mark

919 vs 639 iso
Take photos in low light with less noise
HDMI out
HDMI out vs None
Use HDMI output to monitor or review video
Shoots 24p video
Yes vs No
Gives your movies a big-screen feel
Shoots 1080p video
Yes vs No
You'll want this if you shoot video
Bigger JPEG buffer
100 vs 38 shots
Take more JPEG shots before waiting (burst mode)
Higher extended ISO
12800 vs 6400 ISO
Higher extended ISO can give more low-light flexibility

Similarities

Common Strengths

Eye-level viewfinder
Both provide
You'll be able to frame photos even when the sun is out
Internal flash
Both provide
Useful in a pinch for fill flash
Hot shoe
Both provide
Off-camera flashes open new possibilities
Bulb shutter
Both provide
Hold the shutter open manually for long exposures

Common Weaknesses

Focus peaking
Neither provide
Your camera will highlight what's in focus
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
In-camera panoramas
Neither provide
Stitches multiple shots into a panoramic photo
Tiltable Screen
Neither provide
Tilt the screen for shooting flexbility
Built-in Wi-Fi
Neither provide
Share your photos wirelessly
NFC
Neither provide
Simplifies pairing your camera with supported phones
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
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
Slow-motion videos
Neither provide
Shoot slow-motion videos

Buy From

Your purchases support this site

Buy the Pentax K20D

Your purchases support this site

Buy the Nikon D3100

Review Excerpt

Read our Pentax K20D Full Review

Read our Nikon D3100 Full Review

The Competition

Compared to Samsung GX-20

Pentax K20D

Samsung GX-20

$800
APS-C

Less expensive

$1400
APS-C

Higher effective ISO

Compare Pentax K20D vs Samsung GX-20

Nikon D3100

Samsung GX-20

$700
APS-C

Less expensive
Higher effective ISO

$1400
APS-C

In-Camera Image Stabilization
Top deck display

Compare Nikon D3100 vs Samsung GX-20

Compared to Sony DSLR-A380

Pentax K20D

Sony DSLR-A380

$800
APS-C

Lens selection
Fast startup

$849
APS-C

Tiltable Screen
HDMI out

Compare Pentax K20D vs Sony DSLR-A380

Nikon D3100

Sony DSLR-A380

$700
APS-C

Lens selection
Less expensive

$849
APS-C

In-Camera Image Stabilization
Tiltable Screen

Compare Nikon D3100 vs Sony DSLR-A380

Compared to Pentax K-7

Pentax K20D

Pentax K-7

$800
APS-C

Less expensive
Fast startup

$1300
APS-C

Longer stills battery life
HDMI out

Compare Pentax K20D vs Pentax K-7

Nikon D3100

Pentax K-7

$700
APS-C

Less expensive
Fast startup

$1300
APS-C

In-Camera Image Stabilization
Longer stills battery life

Compare Nikon D3100 vs Pentax K-7

Compared to Sony A33

Pentax K20D

Sony A33

$800
APS-C

Lens selection
Fast startup

$540
APS-C

In-camera panoramas
Tiltable Screen

Compare Pentax K20D vs Sony A33

Nikon D3100

Sony A33

$700
APS-C

Lens selection
Fast startup

$540
APS-C

In-Camera Image Stabilization
In-camera panoramas

Compare Nikon D3100 vs Sony A33

Compared to Pentax K-r

Pentax K20D

Pentax K-r

$800
APS-C

Top deck display
Pentaprism viewfinder

$850
APS-C

Fast startup
Higher effective ISO

Compare Pentax K20D vs Pentax K-r

Nikon D3100

Pentax K-r

$700
APS-C

Less expensive
Higher effective ISO

$850
APS-C

In-Camera Image Stabilization
Fast startup

Compare Nikon D3100 vs Pentax K-r

Compare Other Cameras?