Viofo A139 Pro Review

Viofo A139 Pro Review

Viofo A139 Pro Full Review

Here is our full review on the Viofo A139 Pro Dash Cam.

Dash Cam Options

There are 4 different ways you can get the Viofo A139 Pro dash cam.

  • Option 1 – Front Camera
  • Option 2 – Front and Rear Camera
  • Option 3 – Front, Rear, and Interior Camera

Sony STARVIS 2 Technology

Being the first to deploy the newest Sony STARVIS 2 tech, A139 Pro is powerful enough to outbeat most 4K dashcam competitors with immensely upgraded image clarity and accuracy in license capturing. Sony latest technology STARVIS 2 IMX 678 image sensor, type 1/1.8’’, offers a wider dynamic range in a single exposure than the STARVIS pixel of the same size, bringing much less noise and motion blur during day & night recording.

A little bit of history on Viofo Dash Cams. The Viofo A129 Pro uses a Sony EXMOR sensor up front and a Sony STARVIS rear camera. While, the Viofo A229 (New Pro version available now that uses STARVIS 2) uses a Sony STARVIS image sensor front and back. Last but not least the A139 Pro uses a 4K Sony STARVIS 2 image sensor and a rear STARVIS.

Sony Starvis 1 vs STARVIS 2 comparison

Dash Cam Resolution

Here are the options for various configurations of the Viofo A139 Pro

1 Channel / Front Camera

  • 4K 2160P / 1600P 30fps
  • 2K 1440P 30 / 60fps

2 Channel / Front + Rear / Front and Interior

  • 4K 2160P / 1600P 30fps +1080P 30fps
  • 2K 1440P 30 / 60fps +1080P 30fps

3 Channel / Front + Rear + Interior

  • 4K 2160P 24fps +1080P 24fps + 1080P 24fps
  • 4K 1600P 30fps +1080P 30fps + 1080P 30fps
  • 2K 1440P 30fps +1080P 30fps + 1080p 30 fps

Dash Cam Layout of Viofo A139 Pro

viofo a139 pro dash cam layout


You can set the bitrate for video. High bitrate improve the quality or smoothness of the video especially when recording fast motion or high contrast scenes. Using high bitrate mode may decrease the amount of recording time available on your memory card. Using a low bitrate will save space and record for longer time. Therefore, you can change the bitrate from low, normal, high or maximum on the A139 Pro dash camera. I typically run it on high or maximum frequently. I would recommend the same to everyone else for best quality.

Viewing Angle

The A139 Pro has a front viewing angle of 140 degrees, a rear viewing angle of 170 degrees and an interior viewing angle of 170 degrees. Depending on the configuration will depend on what viewing angles you have available.

Licence Plate Identification

When driving with traffic, I do find it to be the best out of any other dash camera that I have tested on the market. Furthermore, for picking up licence plates during the day or at night which you can see in our example video below. However, picking up licence plates to oncoming traffic still suffers motion blur on the license plate quite frequently. This is still the hardest obstacle for the dash cam technology available. Hopefully we will see some upgrades to firmware of the unit to dial it in over the next little while.

I also seen when driving through a tunnel when raining there are a lot of different contrast levels. There are far too many reflections for it to consistently pick up license plates. Certainly, you will not be driving through tunnels in a rainstorm everyday. But these are some of the challenges that still exist. However, from what i have seen in terms of performance. This is by far the best dash camera for picking up license plates.

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High Dynamic Range

The Viofo A139 pro has high dynamic range. HIGH DYNAMIC RANGE also known as HDR enables the camera to deliver video with near-perfect exposure in varying lighting situations. It can enhance video quality, especially when it comes to the issue of the front license plate being overexposed at night.

high dynamic range on or off comparison


The G-sensor measures shock forces and locks the video recorded at the time. The settings from “low to high” determine the amount of force needed. Depending on your settings you can set the dash cam up to lock the video file recordings. There are different settings for parking mode, and while you are driving.


So, the Viofo A139 Pro has the option of 2.4GHz or 5GHz Wi-Fi. They also have an Android and IOS app so you can connect to the phone, download videos and change settings. Furthermore, if you use the 5GHz setting it will allow you to download videos 3-4 times faster then the 2.4GHz setting.

viofo 5 ghz wi-fi via smartphone app

SD Card Capacity

The Viofo dash camera supports up to 512gb micro SD card as long as it is high endurance or a Viofo SD card.

viofo micro sd cards

GPS Antenna

The Viofo A139 Pro has the GPS antenna built into the dock that the dash camera slides into. This will give you information such as GPS speed and location which will be embedded into the video. If you do not want that information showing up on your video, you can also turn it off.

Parking Mode

  • Auto Event Detection-Automatically record when detecting moving objects or impact while car is parked
  • Time Lapse- Video is recorded at a low frame per second from 1, 2, 3,5, or 10
  • Low bitrate recording – You can lower resolution to save space while recording

Parking Mode Cable / Low Battery Protection

In order to use Parking mode you must hook up constant power, ignition and ground. You must also use the selector switch on the cable to select you low battery cutoff. Therefore, you have the options of 11.8,12,12.2, or 12.4 volts. What this means for you is if the car battery drops below that set voltage, the dash camera will shut off to protect the battery of your car.

viofo parking mode cable hardwire

Loop Recording

Above all, the Viofo A139 Pro offers the options of 1,2,3,5, or 10 minute video loop recordings.

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File List Organization

Viofo organizes their files into 3 folders.

  • All – All video files
  • Locked Files – Impacts, or manual recording / emergency recording button recordings
  • Parking Files – Incidents that happen while parked

Cable Sizes

Part of our Viofo A139 Pro review is how big the cables are in size. What I really love about the A139 Pro is it uses a very small cable for rear camera. When comparing the cable size from an A129 Pro to the A139 Pro. The cable size is 5mm in thickness while the A139 Pro uses a 2.8mm. This makes it easier for technicians during installation or do it yourselfers.

Viofo cable size

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Pro’s and Con’s


  • High Dynamic Range
  • Support up to 512 GB SD card
  • Night Vision
  • Sony STARVIS 2 image sensor
  • Best Dash Cam I have tested for license plates
  • Small rear camera cable


  • 1080P rear camera
  • File organization
  • No app controlled low battery protection
  • No LCD screen

Comparison Video

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Viofo A139 Pro Review Final Thoughts

Overall, this is a new very exciting product with a lot of firsts in terms of the new Sony STARVIS 2 image sensor. There will be other brand new dash cameras coming out with some of the same tech over the next year it is exciting to see how well this unit works. I know personally I use this unit in my car as of late. If you have any questions please email us




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