Sony a9 vs Nikon D5100

This is a full comparison between the cameras Sony a9 and Nikon D5100. We compare them by looking at the categories you see below.

Manufacturing

Sony a9 is manufacturered by Sony but Nikon D5100 is from Nikon. Both Sony and Nikon are well known brands though.

Type of camera

Sony a9 is a Mirrorless camera while Nikon D5100 is a DSLR camera. More information about their differences will come soon.

Sensors / crop factor

These cameras have different sensors. Sony a9 has a "Sony Full Frame"-sensor while Nikon D5100 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 a9 has a 24 MP (Megapixels) resolution while Nikon D5100 has 16,2 MP. If we break down this in more detail this is the data behind the numbers:

Sony a9 has a 49 % larger resolution than Nikon D5100. 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 a9 has a larger ISO-range than Nikon D5100. Sony a9 has an ISO range that stretches from 100 to 51200 while Nikon D5100 has 100 to 6400.

Autofocus and lens compatibility

There is a big difference between these two cameras. Sony a9 has a built-in autofocus motor but Nikon D5100 does not. If you want to be able to use autofocus on Nikon D5100 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 a9
Lens compatibility chart for Nikon D5100

Pictures per second

Depending on what you are shooting the FPS, or frames/pictures per second, can definitely be of interest. Sony a9 can shoot up to 20 pictures per seconds and Nikon D5100 can shoot up to 4 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 a9 and Nikon D5100 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.

Sony a9 weighs 673 gr (equal to 1.48 lb) which is 10% heavier than Nikon D5100 and its 611 gr (or 1.35 lb).

Sony a9 vs Nikon D5100 Specs

Below you will find the complete and detailed technical specs for both Sony a9 and Nikon D5100, 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 a9	Nikon D5100
Name	Sony a9	Nikon D5100
Manufacturer	Sony	Nikon
Release Date and Price	Sony a9	Nikon D5100
Release Year	2017	2011
Release Date	2017-04-19	2011-04-05
MSRP	4499 USD	359 USD
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Camera Type	Sony a9	Nikon D5100
Camera Type	Mirrorless	DSLR
Sensor	Sony a9	Nikon D5100
Sensor Size	Full Frame (approx 36 x 24 mm)	APS-C (approx 23.7 x 15.5 mm) Also known as "DX"
Sensor Type	Stacked CMOS	CMOS
Resolution	6000 x 4000 pixels	4928 x 3264 pixels
Megapixels	24 MP	16,2 MP
Image Processor	Bionz X	EXPEED 2
Image	Sony a9	Nikon D5100
ISO Range	100 - 51200	100 - 6400
White Balance Presets	10	12
Custom White Balance	Yes	Yes
Image Stabilization	Yes (Sensor-Shift (5-axis))	No
Image Stabilization CIPA Rating	0 stops	0 stops
Uncompressed format	RAW	RAW
Optics & Focus	Sony a9	Nikon D5100
Autofocus Motor	Yes	No
Autofocus	Contract Detect (sensor) Phase Detect Multi Area Center Selective Single Point Tracking Single Continuous Touch Face Detection LiveView	Contract Detect (sensor) Phase Detect Multi Area Center Selective Single Point Tracking Single Continuous Face Detection LiveView
Focus Points	693	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 a9	Nikon D5100
Articulated LCD	Tilting	Fully articulated
Screen size	3”	3#
Screen dots	1440000	921000
Touch screen	Yes	No
Screen type	TFT LCD	TFT LCD monitor
Live view	Yes	Yes
Viewfinder Type	Electronic	Optical (pentamirror)
Viewfinder Coverage	100%	95%
Viewfinder Magnification	0.78x	0.78× (0.52× 35mm equiv.)
Viewfinder Resolution	3686400	N/A
Photography features	Sony a9	Nikon D5100
Frames per second	20 fps	4 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	Yes
Metering modes	Multi Center Weighted Highlight Weighted Spot Average	Multi Center Weighted Spot
Exposure Compensation	+/- 5 (at 1/3 EV, 1/2 EV steps)	+/- 5 (at 1/3 EV, 1/2 EV steps)
Videography features	Sony a9	Nikon D5100
Video recording	Yes	Yes
Video format	MPEG4 H.264 AVCHD	MPEG4
Video resolution	1280 x 720 1920 x 1080 3840 x 2160	1280 x 720 1920 x 1080
Built-in Microphone	Yes	Yes
Built-in Speakers	Yes	Yes
Storage	Sony a9	Nikon D5100
Memory Card	SD/SDHC	SD/SDHC
Connectivity	Sony a9	Nikon D5100
HDMI Output	Yes	Yes
Microphone Port	Yes	Yes
Headphone Port	Yes	No
Wireless	Yes Built-in (802.11/b/g/n with NFC)	Yes Eye-Fi Connected
Remote Control	Yes (Wired or wireless)	Yes (Optional ML-L3)
GPS	No	Yes Optional with GP-1
Body & Dimensions	Sony a9	Nikon D5100
Enviromentally sealed	Yes	No
Battery	Battery Pack	Battery Pack
Battery Details	NP-FZ100	Lithium-Ion EN-EL14 rechargeable battery & charger
Battery Life (CIPA)	650 shots	N/A
Width	127 mm	128 mm
Height	96 mm	97 mm
Depth	63 mm	79 mm
Weight	673 gram	611 gram