Sony a6400 vs Sony a9

This is a full comparison between the cameras Sony a6400 and Sony a9. We compare them by looking at the categories you see below.

Manufacturing

These cameras are both manufactured by Sony.

Sony a6400 were released 2019 and Sony a9 was released 2017. That is a 2 years difference. In tech, this period can be of interest since technology is always improving, etc.

Camera Released
Sony a6400 2019
Sony a9 2017

Type of camera

Both these cameras are Mirrorless cameras. No difference there.

Sensors / crop factor

These cameras have different sensors. Sony a6400 has a "Sony APS-C"-sensor while Sony a9 has a "Sony Full Frame"-sensor, and their difference in sensors will also affect the crop factor and experience focal length. See the table below.

Camera Focal length, 50mm f/1.8 **
Sony a6400 75 mm
Sony APS-C sensor
Crop factor/focal length multiplier by * 1.5
Sony a9 50 mm
Full-frame sensor
No crop factor/focal length multiplier

** 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)

Resolution

Both these cameras have the exact same resolution. Sony a6400 has a 24 MP (Megapixels) resolution while Sony a9 has 24 MP. If we break down this in more detail this is the data behind the numbers:

Camera Megapixels
Sony a6400 24 MP
24000000 pixels
6000 x 4000
Sony a9 24 MP
24000000 pixels
6000 x 4000

ISO range

Sony a9 has a larger ISO-range than Sony a6400. Sony a9 has an ISO range that stretches from 100 to 51200 while Sony a6400 has 100 to 32000.

Camera ISO Range
Sony a6400 100-32000
Sony a9 100-51200

Autofocus and lens compatibility

Both of these cameras have a built-in autofocus motor. Some lenses, that support autofocus, do not have an autofocus motor of their own but this won't cause any problems with these two cameras.

Here is a complete overview of which lenses work with each camera:
Lens compatibility chart for Sony a6400
Lens compatibility chart for Sony a9

Pictures per second

Depending on what you are shooting the FPS, or frames/pictures per second, can definitely be of interest. Sony a6400 can shoot up to 11 pictures per seconds and Sony a9 can shoot up to 20 pictures per seconds.

Camera FPS (Frames per second)
Sony a6400 11
Sony a9 20

Ability to record movies

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

In this case, both Sony a6400 and Sony a9 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 67% heavier than Sony a6400 and its 403 gr (or 0.89 lb).

Camera Weight
Sony a6400 403 gr
0.89 lb
Sony a9 673 gr
1.48 lb

Sony a6400 vs Sony a9 Specs

Below you will find the complete and detailed technical specs for both Sony a6400 and Sony a9, 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 a6400
Sony a9
Name Sony a6400 Sony a9
Manufacturer Sony Sony
Release Date and Price
Sony a6400
Sony a9
Release Year 2019 2017
Release Date 2019-01-15 2017-04-19
MSRP 899 USD 4499 USD
Buy it today
Camera Type
Sony a6400
Sony a9
Camera Type Mirrorless Mirrorless
Sensor
Sony a6400
Sony a9
Sensor Size APS-C (approx 23.5 x 15.6 mm) Full Frame (approx 36 x 24 mm)
Sensor Type CMOS Stacked CMOS
Resolution 6000 x 4000 pixels 6000 x 4000 pixels
Megapixels 24 MP 24 MP
Image Processor Bionz X Bionz X
Image
Sony a6400
Sony a9
ISO Range 100 - 32000 100 - 51200
White Balance Presets 10 10
Custom White Balance Yes Yes
Image Stabilization No Yes
(Sensor-Shift (5-axis))
Image Stabilization CIPA Rating 0 stops 0 stops
Uncompressed format RAW RAW
Optics & Focus
Sony a6400
Sony a9
Autofocus Motor Yes Yes
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
Touch
Face Detection
LiveView
Focus Points 425 693
Lens Mount Sony E

See Compatible Lenses
Sony E

See Compatible Lenses
Focal Length Multiplier APS-C Sensor (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
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
Screen & Viewfinder
Sony a6400
Sony a9
Articulated LCD Tilting Tilting
Screen size 3” 3”
Screen dots 921600 1440000
Touch screen Yes Yes
Screen type TFT LCD TFT LCD
Live view Yes Yes
Viewfinder Type Electronic Electronic
Viewfinder Coverage 100% 100%
Viewfinder Magnification 1.07× (0.71× 35mm equiv.) 0.78x
Viewfinder Resolution 2359296 3686400
Photography features
Sony a6400
Sony a9
Frames per second 11 fps 20 fps
Minimum Shutter Speed 30 seconds 30 seconds
Maximum Shutter Speed 1/4000 seconds 1/8000 seconds
Built-in Flash Yes No
Built-in Flash Range 6 meters N/A
External Flash Yes Yes
Self-Timer Yes Yes
Time-lapse Yes No
Metering modes Multi
Center Weighted
Highlight Weighted
Spot
Average
Multi
Center Weighted
Highlight Weighted
Spot
Average
Exposure Compensation +/- 5 (at 1/3 EV, 1/2 EV steps) +/- 5 (at 1/3 EV, 1/2 EV steps)
Videography features
Sony a6400
Sony a9
Video recording Yes Yes
Video format MPEG4
H.264
MPEG4
H.264
AVCHD
Video resolution 1920 x 1080
3840 x 2160
1280 x 720
1920 x 1080
3840 x 2160
Built-in Microphone Yes Yes
Built-in Speakers Yes Yes
Storage
Sony a6400
Sony a9
Memory Card Memory Stick Pro Duo
SD/SDHC
SD/SDHC
Connectivity
Sony a6400
Sony a9
HDMI Output Yes Yes
Microphone Port Yes Yes
Headphone Port No Yes
Wireless Yes
Built-in (802.11b/g/n + NFC + Bluetooth 4.1)
Yes
Built-in (802.11/b/g/n with NFC)
Remote Control Yes (via smartphone) Yes (Wired or wireless)
GPS No No
Body & Dimensions
Sony a6400
Sony a9
Enviromentally sealed Yes Yes
Battery Battery Pack Battery Pack
Battery Details NP-FW50
NP-FZ100
Battery Life (CIPA) 410 shots 650 shots
Width 120 mm 127 mm
Height 67 mm 96 mm
Depth 60 mm 63 mm
Weight 403 gram 673 gram