Sony a7 vs Nikon D3100

This is a full comparison between the cameras Sony a7 and Nikon D3100. We compare them by looking at the categories you see below.

Manufacturing

Sony a7 is manufacturered by Sony but Nikon D3100 is from Nikon. Both Sony and Nikon are well known brands though.

Type of camera

Sony a7 is a Mirrorless camera while Nikon D3100 is a DSLR camera. More information about their differences will come soon.

Sensors / crop factor

These cameras have different sensors. Sony a7 has a "Sony Full Frame"-sensor while Nikon D3100 has a "Nikon DX"-sensor, and their difference in sensors will also affect the crop factor and experience focal length. See the table below.

** Experienced focal length when using a lens such as a common "50mm f/1.8"

Learn more about crop factor and focal length multiplier here:
Camera selection can affect the focal length (Sony)
Camera selection can affect the focal length (Nikon)

Resolution

Sony a7 has a 24 MP (Megapixels) resolution while Nikon D3100 has 14,2 MP. If we break down this in more detail this is the data behind the numbers:

Sony a7 has a 70 % larger resolution than Nikon D3100. This could give you more details in the picture but also a possibility to crop more in the pictures, afterward while editing the pictures, if needed that is.

ISO range

Sony a7 has a larger ISO-range than Nikon D3100. Sony a7 has an ISO range that stretches from 100 to 25600 while Nikon D3100 has 100 to 12800.

Autofocus and lens compatibility

There is a big difference between these two cameras. Sony a7 has a built-in autofocus motor but Nikon D3100 does not. If you want to be able to use autofocus on Nikon D3100 there is a need for having an autofocus motor inside the lens. We really encourage you to look closely at our lens compatibility charts at the links below.

Here is a complete overview of which lenses work with each camera:
Lens compatibility chart for Sony a7
Lens compatibility chart for Nikon D3100

Pictures per second

Depending on what you are shooting the FPS, or frames/pictures per second, can definitely be of interest. Sony a7 can shoot up to 5 pictures per seconds and Nikon D3100 can shoot up to 3 pictures per seconds.

Ability to record movies

It is becoming more and more popular to record movies with digital cameras.

In this case, both Sony a7 and Nikon D3100 can shoot movies.

Weight

The weight of the camera can be an extremely important factor, especially if the camera is about to be used, or carried around, for several hours at a time.

Nikon D3100 weighs 505 gr (equal to 1.11 lb) which is 7% heavier than Sony a7 and its 474 gr (or 1.04 lb).

Sony a7 vs Nikon D3100 Specs

Below you will find the complete and detailed technical specs for both Sony a7 and Nikon D3100, next to each other. Each category of data is a link to an article covering the subject, giving you a deeper understanding so you can better understand the strengths and weaknesses of the two camera models.

Product	Sony a7	Nikon D3100
Name	Sony a7	Nikon D3100
Manufacturer	Sony	Nikon
Release Date and Price	Sony a7	Nikon D3100
Release Year	2013	2010
Release Date	2013-10-16	2010-08-19
MSRP	1699 USD	699 USD
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Camera Type	Sony a7	Nikon D3100
Camera Type	Mirrorless	DSLR
Sensor	Sony a7	Nikon D3100
Sensor Size	Full Frame (approx 36 x 24 mm)	APS-C (approx 23.7 x 15.5 mm) Also known as "DX"
Sensor Type	CMOS	CMOS
Resolution	6000 x 4000 pixels	4608 x 3072 pixels
Megapixels	24 MP	14,2 MP
Image Processor	Bionz X	EXPEED 2
Image	Sony a7	Nikon D3100
ISO Range	100 - 25600	100 - 12800
White Balance Presets	10	12
Custom White Balance	Yes	Yes
Image Stabilization	No	No
Image Stabilization CIPA Rating	0 stops	0 stops
Uncompressed format	RAW	RAW
Optics & Focus	Sony a7	Nikon D3100
Autofocus Motor	Yes	No
Autofocus	Contract Detect (sensor) Phase Detect Multi Area Center Selective Single Point Single Continuous Face Detection LiveView	Contract Detect (sensor) Phase Detect Multi Area Selective Single Point Tracking Single Continuous Face Detection LiveView
Focus Points	117	11
Lens Mount	Sony E See Compatible Lenses	Nikon F See Compatible Lenses
Focal Length Multiplier	Full frame No multiplier Example: 24 mm remains 24 mm 50 mm remains 50 mm 100 mm remains 100 mm 200 mm remains 200 mm	DX / APS-C (1.5x) 1.5x multiplier Example: 24 mm becomes 36 mm 50 mm becomes 75 mm 100 mm becomes 150 mm 200 mm becomes 300 mm
Screen & Viewfinder	Sony a7	Nikon D3100
Articulated LCD	Tilting	Fixed
Screen size	3”	3”
Screen dots	1230000	230000
Touch screen	No	No
Screen type	Xtra Fine LCD	TFT LCD monitor
Live view	Yes	Yes
Viewfinder Type	Electronic	Optical (pentamirror)
Viewfinder Coverage	100%	95%
Viewfinder Magnification	0.71×	0.8× (0.53× 35mm equiv.)
Viewfinder Resolution	N/A	N/A
Photography features	Sony a7	Nikon D3100
Frames per second	5 fps	3 fps
Minimum Shutter Speed	30 seconds	30 seconds
Maximum Shutter Speed	1/8000 seconds	1/4000 seconds
Built-in Flash	No	Yes
Built-in Flash Range	N/A	12 meters
External Flash	Yes	Yes
Self-Timer	Yes	Yes
Time-lapse	No	No
Metering modes	Multi Center Weighted Spot	Multi Center Weighted Average
Exposure Compensation	+/- 5 (at 1/3 EV, 1/2 EV steps)	+/- 5 (at 1/3 EV steps)
Videography features	Sony a7	Nikon D3100
Video recording	Yes	Yes
Video format	MPEG4 AVCHD	MPEG4
Video resolution	1440 x 1080 1920 x 1080	1280 x 720 1920 x 1080
Built-in Microphone	Yes	Yes
Built-in Speakers	Yes	No
Storage	Sony a7	Nikon D3100
Memory Card	Memory Stick Pro Duo SD/SDHC	SD/SDHC
Connectivity	Sony a7	Nikon D3100
HDMI Output	Yes	Yes
Microphone Port	Yes	No
Headphone Port	Yes	No
Wireless	Yes Built-In ( with NFC and wireless control via PlayMemories Mobile app)	Yes Eye-Fi Connected
Remote Control	Yes (wired)	Optional
GPS	No	Yes Optional
Body & Dimensions	Sony a7	Nikon D3100
Enviromentally sealed	Yes	No
Battery	Battery Pack	Battery Pack
Battery Details	NP-FW50 lithium-ion battery and charger	Lithium-Ion EN-EL14 rechargeable battery & charger
Battery Life (CIPA)	340 shots	N/A
Width	127 mm	124 mm
Height	94 mm	96 mm
Depth	48 mm	75 mm
Weight	474 gram	505 gram