Viofo

Viofo A139 Pro 2CH

Name: Viofo A139 Pro 2CH
Brand: Viofo
Price: 250 USD
Availability: InStock

No rating shown: we have no owner rating for this camera from a source we can cite. Why

4K frontSupercapacitorVoice control5 GHz Wi-FiCPL includedScreenless25+ px/°

Viofo's A139 Pro is the screenless one. Its body is a squat cylinder that sits flat against the glass behind the mirror with no display at all, which is the right shape if you want the camera invisible from outside the car and do not want a lit rectangle in your peripheral vision at night. Everything is done through the phone app over 5GHz Wi-Fi. The front camera is an 8MP Sony STARVIS 2 IMX678 at 3840x2160/30 behind an f/1.6 lens quoted at 140 degrees - that f/1.6 is a stop faster than the newer A229 Pro's f/1.8 on the same sensor, which is the specific reason people still choose the A139 Pro for badly lit streets. The rear is a 2MP IMX291 at 1080p on a 165-degree lens. A CPL filter for the front camera is in the box rather than an upsell, which is unusual and worth about thirty dollars. Supercapacitor power, built-in GPS, Bluetooth remote support and voice control are all standard; parking modes need the Type-C HK3-C hardwire kit.

Approx. price: ~$250
Hot car: Supercapacitor; Supercapacitor, rated to 149°F
Parking tier: Buffered; Hardwire kit optional

Best for

A discreet 4K install where nothing should be visible from outside the car.

The description and the pros and cons above are written from published specifications, not from owner reports. Owner sentiment, where we have it, is in its own section below.

What the numbers mean here

The front camera records 3,840 horizontal pixels across a published 140-degree field of view, which is 27.4 pixels per degree — plate-legible at distance. The rear channel manages 11.6, so it is the less detailed of the two. How this is calculated, and what it does not tell you.

It runs on a supercapacitor rather than a lithium cell, so there is no battery to swell in a car parked in summer sun — the classic way a windshield-mounted camera dies. The maker publishes an operating range of -4°F to 149°F. Supercapacitors and heat.

Keeps a rolling buffer, so the seconds before an impact are saved as well as the impact itself. It is the most useful parking mode and the hungriest. The hardwire kit is a separate purchase, which is the line item people forget when budgeting. What each parking mode records.

Specifications

Manufacturer-published figures, recorded from Viofo’s own product page and a specialist retailer’s spec table. Fields the maker does not publish are omitted rather than guessed.

Type: Dual-channel
Channels: 2
Front resolution: 2160p
Front frame rate: 30fps
Front sensor: Sony STARVIS 2 IMX678
Front field of view: 140° (as published)
Front aperture: f/1.6
Rear resolution: 1080p
Rear sensor: Sony STARVIS IMX291
Rear field of view: 165°
HDR: HDR
Power cell: Supercapacitor
Operating temperature: -4°F to 149°F
Parking modes: buffered, time-lapse, low-bitrate, motion
Hardwire kit: optional
GPS: built-in
Wi-Fi: 5 GHz
LTE / cloud: None
Max storage: 512GB microSD
CPL filter: included
Screen: None
Voice control: Yes
Form factor: cylinder
Mount: adhesive
Release year: 2023

Features

Front 3840x2160 at 30fps with HDR on a Sony STARVIS 2 IMX678
f/1.6 front lens - a stop faster than the A229 Pro on the same sensor
Rear 1080p on a 165-degree Sony STARVIS IMX291
Completely screenless cylindrical body, app-only control
CPL filter included in the box
5GHz Wi-Fi, built-in GPS, Bluetooth remote support, voice control
Supercapacitor, -4 to 149 degrees Fahrenheit, microSD to 512GB

Where it is strong

f/1.6 aperture on a 4K STARVIS 2 sensor is the fastest 4K optic in this catalog - the reason it still outsells newer models on dark streets
No screen means nothing glows at night and nothing signals to a passerby that there is a camera worth taking
CPL filter included rather than sold separately, which is a real thirty-dollar difference against rivals
The cylinder sits flatter against the glass than a wedge, so it clears more windshield rake
5GHz Wi-Fi and 512GB card support keep 4K downloads and long loops practical

Where it gives way

No screen means no way to check framing without a phone, which makes the initial aim fiddly
The rear channel is only 1080p on an older IMX291, a real step behind the 2K rear cameras in this price bracket
Parking mode needs the HK3-C kit, which is a separate purchase
The cylindrical body is harder to hide behind a small mirror than the mini wedges

What owners say

Summarised from public owner discussion. Nothing here is our own testing.

The A139 Pro is bought for two reasons and owner discussion reflects both. The first is that it has no screen at all, so nothing lights up the cabin at night and nothing signals from outside the car that there is a camera worth stealing. The second is the f/1.6 lens, which is a stop faster than the newer A229 Pro on the same sensor and is why people who drive dark roads still choose the older model.

Power draw is what owners warn each other about. Owners describe it as a hog in parking mode and several have traced a flat battery to it, so the low-voltage cutoff on the hardwire kit is not optional here - it is the thing standing between you and a jump start. Owners also report needing a specific hardwire cable rather than the generic kit to get parking mode working at all in some installs, which is worth confirming with the retailer before you start.

Two smaller irritations: voice prompts that people regularly want turned off, and the absence of a screen, which makes the first aim-and-check fiddlier than it needs to be.

What owners like

The screenless body is the reason people choose it - owners specifically want nothing glowing at night and nothing visible from outside the car
Owners rate the night image highly and the fast f/1.6 lens is the reason usually given
5GHz Wi-Fi makes 4K clips practical to pull, which owners moving up from a 2.4GHz camera notice immediately
The included front CPL filter saves a purchase that owners of rival cameras end up making anyway

Common complaints

It has a reputation among owners as a power hog in parking mode, with several attributing a flat car battery to it
Heat is a live question - owners ask directly whether it struggles more than the A229 in a hot car, and nobody has a confident answer
Getting parking mode working needs the right cable: owners have been told by retailers that the standard kit is not enough and a specific hardwire cable is required for their setup
The voice prompts annoy enough owners that 'can these be turned off' is a recurring question
With no screen there is no way to confirm framing or check a clip without a phone, which slows the first install down

What owners of the Viofo A139 Pro 2CH ask

Does the A139 Pro drain a car battery?

It draws more in parking mode than most of the catalog and owners have traced flat batteries to it. Set the hardwire kit's low-voltage cutoff conservatively - the higher settings stop the camera well before the car will not start - and consider a dedicated battery pack if you park for days at a time.

Is it better than the A229 Pro at night?

Owners choosing between them on night performance generally pick the A139 Pro, because its f/1.6 lens is a stop faster than the A229 Pro's f/1.8 on the same 8MP sensor. The A229 Pro wins on everything else - screen, voice control, newer firmware, a 1440p rear camera instead of 1080p.

Can I turn off the voice prompts?

Yes, the voice notifications are a menu setting and can be disabled without turning off audio recording. This is one of the most commonly asked questions about the camera, mostly from owners who find the startup announcements intrusive on short trips.

Which hardwire kit do I need?

The Type-C HK3-C is the standard kit for the A139 and A139 Pro. Some owners have been told by retailers that their specific setup needs a different cable, so if parking mode will not engage after a correct-looking install, check the cable part number against your camera revision before assuming the camera is faulty.