Sony a9 II vs Sony a55

This is a full comparison between the cameras Sony a9 II and Sony a55. We compare them by looking at the categories you see below.

Manufacturing

These cameras are both manufactured by Sony.

Sony a9 II were released 2019 and Sony a55 was released 2010. That is a 9 years difference. In tech, this period can be of interest since technology is always improving, etc.

Camera Released
Sony a9 II 2019
Sony a55 2010

Type of camera

Sensors / crop factor

These cameras have different sensors. Sony a9 II has a "Sony Full Frame"-sensor while Sony a55 has a "Sony APS-C"-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 a9 II 50 mm
Full-frame sensor
No crop factor/focal length multiplier
Sony a55 75 mm
Sony APS-C sensor
Crop factor/focal length multiplier by * 1.5

** 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

Sony a9 II has a 24 MP (Megapixels) resolution while Sony a55 has 16 MP. If we break down this in more detail this is the data behind the numbers:

Camera Megapixels
Sony a9 II 24 MP
24000000 pixels
6000 x 4000
Sony a55 16 MP
16032768 pixels
4912 x 3264

Sony a9 II has a 50 % larger resolution than Sony a55. 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 II has a larger ISO-range than Sony a55. Sony a9 II has an ISO range that stretches from 100 to 51200 while Sony a55 has 100 to 12800.

Camera ISO Range
Sony a9 II 100-51200
Sony a55 100-12800

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 a9 II
Lens compatibility chart for Sony a55

Pictures per second

Depending on what you are shooting the FPS, or frames/pictures per second, can definitely be of interest. Sony a9 II can shoot up to 20 pictures per seconds and Sony a55 can shoot up to 10 pictures per seconds.

Camera FPS (Frames per second)
Sony a9 II 20
Sony a55 10

Ability to record movies

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

In this case, both Sony a9 II and Sony a55 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 II weighs 678 gr (equal to 1.49 lb) which is 36% heavier than Sony a55 and its 500 gr (or 1.1 lb).

Camera Weight
Sony a9 II 678 gr
1.49 lb
Sony a55 500 gr
1.1 lb

Sony a9 II vs Sony a55 Specs

Below you will find the complete and detailed technical specs for both Sony a9 II and Sony a55, 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 II
Sony a55
Name Sony a9 II Sony a55
Manufacturer Sony Sony
Release Date and Price
Sony a9 II
Sony a55
Release Year 2019 2010
Release Date 2019-10-03 2010-08-24
MSRP 4499 USD 749 USD
Buy it today
Camera Type
Sony a9 II
Sony a55
Camera Type Mirrorless SLT
Sensor
Sony a9 II
Sony a55
Sensor Size Full Frame (approx 36 x 24 mm) APS-C (approx 23.5 x 15.6 mm)
Sensor Type Stacked CMOS CMOS
Resolution 6000 x 4000 pixels 4912 x 3264 pixels
Megapixels 24 MP 16 MP
Image Processor Bionz X Bionz
Image
Sony a9 II
Sony a55
ISO Range 100 - 51200 100 - 12800
White Balance Presets 9 6
Custom White Balance Yes Yes
Image Stabilization Yes
(Sensor-Shift (5-axis))
Yes
(Sensor-Shift)
Image Stabilization CIPA Rating 5.5 stops 0 stops
Uncompressed format RAW RAW
Optics & Focus
Sony a9 II
Sony a55
Autofocus Motor Yes Yes
Autofocus Contract Detect (sensor)
Phase Detect
Multi Area
Center
Selective Single Point
Tracking
Single
Continuous
Touch
Face Detection
LiveView
Phase Detect
Multi Area
Selective Single Point
Single
Continuous
Face Detection
LiveView
Focus Points 693 15
Lens Mount Sony E

See Compatible Lenses
Sony A

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
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
Screen & Viewfinder
Sony a9 II
Sony a55
Articulated LCD Tilting Fully articulated
Screen size 3” 3”
Screen dots 1440000 921000
Touch screen Yes No
Screen type TFT LCD N/A
Live view Yes Yes
Viewfinder Type Electronic Electronic
Viewfinder Coverage 100% 100%
Viewfinder Magnification 0.78x 1.1× (0.73× 35mm equiv.)
Viewfinder Resolution 3686400 N/A
Photography features
Sony a9 II
Sony a55
Frames per second 20 fps 10 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 10 meters
External Flash Yes Yes
Self-Timer Yes Yes
Time-lapse Yes No
Metering modes Multi
Center Weighted
Highlight Weighted
Spot
Average
Multi
Center Weighted
Spot
Exposure Compensation +/- 5 (at 1/3 EV, 1/2 EV steps) +/- 2 (at 1/3 EV steps)
Videography features
Sony a9 II
Sony a55
Video recording Yes Yes
Video format MPEG4
H.264
AVCHD
MPEG4
H.264
AVCHD
Video resolution 1280 x 720
1920 x 1080
3840 x 2160
1440 x 1080
1920 x 1080
Built-in Microphone Yes Yes
Built-in Speakers Yes No
Storage
Sony a9 II
Sony a55
Memory Card SD/SDHC
Memory Stick Pro Duo
SD/SDHC
Connectivity
Sony a9 II
Sony a55
HDMI Output Yes Yes
Microphone Port Yes No
Headphone Port Yes No
Wireless Yes
Built-in (802.11ac + NFC + Bluetooth)
Yes
Eye-Fi Connected
Remote Control Yes (Wired or wireless) Yes (Optional)
GPS No Yes
Built-in
Body & Dimensions
Sony a9 II
Sony a55
Enviromentally sealed Yes No
Battery Battery Pack Battery Pack
Battery Details NP-FZ100
Rechargeable NP-FW50 battery & charger
Battery Life (CIPA) 690 shots 380 shots
Width 129 mm 124 mm
Height 96 mm 92 mm
Depth 76 mm 85 mm
Weight 678 gram 500 gram