The complete guide
How to Choose a 4K Front and Rear Dash Cam
The problem a dash cam actually solves
Car insurance disputes are rarely about who was right. They are about who can prove it. Two drivers walk away from a junction with completely different accounts of what happened, and in the absence of evidence the result often comes down to a coin toss between insurers. That costs money, time and in some cases a no-claims discount that took years to build.
A dash cam removes the argument. It is a small camera that sits on your windscreen and records continuously while you drive. If something happens, the footage exists. If nothing happens, the footage quietly overwrites itself and you never think about it again. That is the whole idea.
The other thing it covers is everything that happens when you are not in the car. Car park scrapes, door dings, someone reversing into your bumper and leaving. These are not dramatic events, but they are expensive ones, and they are the most common reason people go looking for a car camera front and rear rather than a single front unit.
Why front and rear matters
A front-only camera covers the direction you are looking. That is useful, but it misses a large share of real incidents. Rear-end collisions are one of the most common crash types on the road, and a front camera records nothing at all when someone runs into the back of you.
A dual setup records both. The REDTIGER F9 puts 4K at the front and 1080P at the rear, which is the usual and sensible split. The front camera does the heavy lifting because it covers the direction of travel, where number plates and sign detail matter most. The rear camera needs enough resolution to show a vehicle, its colour and how it was behaving, and 1080P does that.
If you only ever drive on quiet roads and park in a locked garage, a single camera might be enough. For anyone who commutes, parks on the street, or drives for work, the second channel earns its place quickly.
How the recording side works
Dash cams do not record one enormous file. They write in short segments, usually one to three minutes each, and when the memory card fills up the camera starts overwriting the oldest segments. That is loop recording, and it is why you never have to think about storage.
The F9 supports microSD cards up to 256GB, and the card is not included. Buy a high endurance card. Standard cards are built for occasional photos and short videos, not for writing continuously for hours every day, and they fail sooner than people expect. A card rated for dash cam or surveillance use costs a little more and lasts a lot longer.
The G-sensor is the part that protects important footage from the loop. It detects sudden movement, the kind that comes with a hard brake or an impact, and locks the surrounding clip so it cannot be overwritten. This is why the best dash cam with G-sensor is a phrase worth searching. Without it, your most important thirty seconds can be erased on a long drive home.
Built-in GPS adds speed and location data to the files. That context is often what makes footage persuasive rather than just interesting.
Night driving and lens quality
Resolution gets the attention, but light collection does the work after dark. A sensor can only resolve what the lens lets through, and the F9 uses an f/1.5 maximum aperture, which is a wide opening. More light reaching the sensor means less noise, better colour and a better chance of reading a plate under sodium street lights.
The 170 degree field of view is the other number worth looking at. A wide lens sees the full width of the road rather than a narrow strip ahead. Incidents that start at the edges, such as a merge, a cyclist or a car coming off a side street, get captured instead of being half out of frame.
Keep in mind that a dash cam shoots through your windscreen. A dirty or smeared screen will undo a lot of good optics, so clean the glass inside and out when you fit the camera.
Living with the app
Older dash cams made retrieving footage a chore. You pulled the card, hunted for a reader, and hoped your laptop was nearby. Built-in WiFi changed that. The F9 creates its own connection that your phone joins directly, with no internet or mobile data needed, and the REDTIGER app handles live view, playback, downloads and settings.
In practice this is the feature you will use most. Someone clips your mirror in a car park and within two minutes you have the clip saved to your phone and ready to send. Anyone comparing options for the best dash cam with app control is usually comparing exactly this experience.
It also makes the camera easier to configure. Once the unit is mounted up near the mirror, its 3 inch screen is awkward to reach. Changing settings on your phone instead is far more pleasant.
Parking mode and power
Parking mode is what lets the camera keep watching while the car is off. It can record impacts and time-lapse footage of the surroundings. The catch is power, because most 12V sockets go dead when the ignition does.
That is why a hardwire kit is required. It connects the camera to your fuse box so it draws a small, managed amount of power while parked, usually with voltage protection to stop it draining the battery flat. The kit is not included with the camera. If parking protection is the main reason you are buying, budget for one, and consider having it fitted professionally if you are not comfortable working near a fuse box.
The F9 uses a built-in supercapacitor rather than a lithium battery. Supercapacitors cope much better with the heat and cold a windscreen sees across a year. Their role is not to power long recording sessions but to safely finish writing the current file when power is cut.
Fitting it well
Mount the camera high, behind or beside the rear view mirror. That gives a clear view over the bonnet and keeps the unit out of your eyeline. The F9 is small, around 5 x 7 x 6.3 cm and 104 g, with a low profile body intended to sit close to the glass.
Clean the mounting area first with an alcohol wipe so the suction cup holds properly. Route the power cable along the headlining and down the A-pillar trim rather than letting it dangle. Tuck the rear camera cable along the same side of the car, following existing trim lines.
Before you finalise anything, sit in the driver's seat and check your view. Also check your local regulations, because rules about what can sit on a windscreen vary by region.
Keeping it working
Maintenance is light but not optional. Wipe the lens with a dry microfibre cloth when it looks hazy. Format the memory card in the camera every few weeks, since continuous writing is hard on flash memory and regular formatting keeps things tidy. If clips start failing or the camera reports card errors, replace the card rather than hoping it settles.
Every month or so, play back a recent clip. It takes thirty seconds and confirms the whole chain is working. A dash cam you assume is recording and is not is worse than no dash cam at all.
The short version
If you want a camera that covers both ends of your car, the F9 gives you 4K at the front, 1080P at the rear and a 170 degree view through an f/1.5 lens. WiFi and the app make getting footage off it genuinely easy. Loop recording, a G-sensor and GPS handle the background work without you touching anything.
Add a high endurance microSD card up to 256GB, since one is not included. Add a hardwire kit if you want parking mode. Mount it near the mirror, check it occasionally, and then forget about it until the day you need it.