Dash cams have become incredibly popular car accessories in recent years, keeping a faithful eye on the road ahead and recording footage when a collision is detected. Some even boast driver-assistance systems to help keep you alert and safe.
But what if an incident happens behind you? Say someone drives into the back of your car, but isn’t willing to accept the blame, or even fled the scene before you had a chance to stop? This is where a second, rear-facing dash cam could come to the rescue.
These cameras work in a very similar way to their front-facing relatives, but tend to be smaller, shoot in a slightly lower resolution, and in most cases connect to the front camera with a long cable. In most cases, the front-facing camera is where the incident detection, processing and storage takes place, with footage from both cameras sent to the front unit and stored on a single microSD card. The rear camera has no display or buttons, and is little more than a secondary camera.
Several prominent dash cam manufacturers also sell rear cameras, which can be attached to the main unit. Thinkware, Nextbase and Blackvue all sell such cameras, and Garmin’s Auto Sync lets you wirelessly connect up to four cameras to one system, all recording footage in unison.
As an alternative, some dash cams have two cameras housed in the same unit; one faces forwards through the windscreen and another faces rearwards, recording the interior of the car. This is unlikely to capture the registration number of a car crashing into the back of you, but is instead useful for recording passengers, and as such is intended for taxi drivers.
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How to choose the best front and rear dash cam for you
Much of this has already been covered in T3’s best dash cam buying guide. But it is worth repeating here that video quality is crucial, along with field-of-view, ease-of-use, reliability, and a discrete design.
Nextbase and Thinkware both sell rear cameras that connect to your existing dash cam. So if you already own a compatible front-facing camera, it’s easy to buy a compatible rear camera and plug it in. Or, both cameras can be bought as a package and installed at the same time.
Interestingly, Nextbae sells two types of rear-facing cameras. One connects directly into the side of the front-facing camera on your windscreen, recording through the interior of your car. The other mounts to the rear windscreen and then connects to the front camera using a long cable.
Naturally, running a cable from the front windscreen to the rear will take considerable effort if you want it to be hidden. Most buyers should consider paying a professional to ensure a neat finish, with the cable hidden behind the interior trim of your car.
One point to make clear is how adding a rear camera only adds a rearview to your system. If the front camera doesn’t have GPS, then adding a rear camera module won’t change this. The same goes for other features like voice control, Wi-Fi and driver assistance; all the new module adds is a rearwards-facing camera.
The Thinkware U1000 dash cam can be bought on its own or with the company’s Rear View Camera. The front-facing camera shoots 4K video for increased resolution and detail over an HD or 2K camera, while the rear camera records in up to 2K.
Thinkware’s rear dash cam is compatible with a range of its front cameras, but its resolution varies depending on which model it is plugged into. 2K resolution (2560 x 1440) is possible when used with the U1000 mentioned here, but that drops to Full HD (1920 x 1080) when used with the Thinkware Q800Pro, QA100 Elite, F800Pro, F800 and X700. The resolution of the rear camera then drops to HD (1440 x 720) with the Thinkware FA200, F200 and F100. The frame rate is 30fps in all cases.
The rear camera is cylindrical and attached to a small windscreen mount with an adhesive strip for sticking into place. The camera can then be rotated to point at the right angle, which will vary depending on the height of the vehicle and rake of the screen. Footage captured by the rear camera is stored on the same microSD card as used by the front camera. When hardwired to the vehicle, both cameras offer motion detection to record footage while parked.
Driver assistance features, which are powered by the front-facing U1000 camera, including red light and speed camera warnings, plus warnings for average and mobile speed cameras, all using the unit’s GPS.
Like Thinkware, Nextbase also sells a rear camera that is compatible with a range of its dash cams. But, similarly, the quality of the rear camera depends on which front-facing dash cam it is connected to.
When connected to the current Nextbase flagship, the 4K-shooting 622GW, the rear camera records at 1080p Full HD. This is also true when connected to the 522GW and the 422GW, but with these there is also the option to lower the quality to 720p HD, which could be handy if you don’t want to quickly fill a smart microSD card with large files. Lastly, the rear camera sticks to 720p HD when used with the 322GW dash cam.
We always say a higher resolution is better when it comes to dash cams, but which you buy here will of course depend on your budget. Footage from both cameras is saved to a memory card inserted into the front-facing cam. The rear camera has a 140-degree lens and comes with a cable that is six metres long which should be plenty to route discreetly around the interior, or through the roof lining, of most cars.
Nextbase employs a magnetic mount for the rear camera. The mount attaches to the rear windscreen using adhesive, then the ball-shaped camera snaps magnetically to the mount. The round shape means the camera can be positioned at almost any angle to ensure a good view of the road behind.
It is worth noting how the rear camera is not compatible with the 512GW or the 380GWX.
A top-notch dash cam, the Nextbase 622GW shoots in 4K through a polarising filter, or with slow motion at 120fps and 1080p if you so wish, and has features like Alexa and What3words built-in. There’s a 3.0-inch touchscreen on the rear and dual-band Wi-Fi for connecting to the companion smartphone app.
Not a dual-camera system as such, but Garmin's Auto Sync feature is worth a mention.
This is compatible with a range of the company's dash cams and lets you pair up to four together, with them all recording picture-in-picture views to their own microSD cards in unison. This means a driver could fit dash cams to the front, rear and even both sides of their vehicle – something that could be particularly useful for owners of motorhomes, vans and other large vehicles.
As for the Garmin Dash Cam 67W, this is a top-notch dash cam with 1440p resolution plus HDR at 60 frames per second, a wide 180-degree viewing angle, integrated GPS and a 2.0-inch LCD display. There's also voice recognition, too.
Garmin's Auto Sync feature is compatible with the Dash Cam 46, 47, 56, 57, 66W, 67W, Mini, Mini 2 and Tandem.
This is the current flagship front+rear dash cam set from Blackvue. The front-facing camera records in 4K resolution with an 8.0-megapixel sensor, while the smaller rear camera captures footage in Full HD. The front-facing field-of-view is 162 degrees while the rearview is a little tighter, at 139 degrees. Both cameras record video at 60 frames per second, ensuring smooth footage.
WiFi and GPS are both included, and Blackvue also sells an option 4G module to give the camera system an always-on data connection for remote notifications and live viewing. The data connection also enables two-way voice calls, where you can speak with whoever is in your car remotely.
There’s also a parking mode that uses motion and vibration sensors to detect events and record footage in a bid to catch evidence of vandalism or a parking incident. Both cameras use a cylindrical design that makes them more compact than some others, and while this means they lack a display, this should make the system less distracting to the driver. It’s very much a set-it-and-forget-it design that doesn’t need interacting with once set up.
As with other dual cameras, the Blackvue uses a long cable to connect the two together. You will likely want to get this professionally installed for the neatest result.
A more affordable option from Blackvue, this is the company’s lowest-priced dual-camera system. It has a similar, cylindrical design to other Blackvue dash cams and records in Full HD 1080p resolution to the front and rear. The footage is captured at 30 frames per second and there is a night vision mode to improve low-light recordings.
The front-facing camera has a 139-degree lens and the rear is slightly narrower at 137 degrees. These are a light tighter than some other options out there, but should still be enough to capture a good outward view from most vehicles.
The camera system has WiFi for connecting to your smartphone or tablet, where the Blackvue app is used to set everything up, and GPS can be added as an optional extra.
There is no display on either camera, but some drivers will prefer this as it makes for a more subtle and less distracting design. Each camera attaches to the windscreen with an adhesive pad, and can be rotated on its mount to point at the right angle to matter the rake of the screen.
Two cameras are all well and good, but what about three? This dash cam system from Zenfox has the usual front- and rear-facing cameras connected to each other with a long cable, but also includes a third camera to monitor the interior.
This is attached to the back of the front-facing camera and is designed to provide even more evidence in the event of a collision, and would be particularly useful for passenger monitoring in taxis and minicabs.
The front camera has the highest specification, with a 1440p resolution and 160-degree lens, while the two rear-facing cameras record in 1080p Full HD and each have a viewing angle of 140 degrees. GPS is included for adding speed and locational data to recordings, and the front camera has a small, 2-inch display on the back.