What does a dash cam do?
A dash cam, sometimes referred to as a dashboard camera is an eyewitness for events that happen in and around your car.
There are many situations where a dash cam be useful and some examples are:
It can provide video evidence in the event of an accident and prove you were not at fault. Similarly, even if you are not involved in an accident your video may help other drivers. Also, it can be the difference in a road rage incident especially if you have to go to court. Your dash cam footage might be the difference between a guilty or not guilty verdict.
Your dash cam can also save you from an unjust ticket. Here is a situation, you are stopped for speeding but the cop’s radar clocked the car that was passing by and you get the ticket. The dash cam video backs up your story when you go to court.
Another could be a ticket for running a red light and your video shows it was yellow when you entered the intersection.
Not to mention, a dash cam can help keep corrupt police honest knowing they are being recorded. Yes, they usually have their own cameras too but it is not unheard for incriminating videos of police misconduct to be “accidently” lost when the court date comes around.
Lastly, you will have some good videos to share on YouTube of the stupid and funny things that people do behind the wheel.
The number of channels is another term for the number of cameras.
A one-channel (1CH) dash cam has one camera, usually facing forward. This is the most basic dash cam setup.
A two-channel (2CH) dash cam has a front rear camera. There are some 2CH dash cams that use the rear camera to record inside the vehicle and these are popular with rideshare and taxi drivers.
A three-channel (3CH) dash cam has a front, interior, and rear facing camera. This is mostly for rideshare or taxi drivers that want full exterior and interior video.
Nearly all dash cams today are 1080p or better. However, as the price of technology drops, 2K cameras have become increasingly common. This is a step above 1080p in terms of detail and video quality. The best resolution currently available for a dash cam is 4K UHD and in the future expect to see more models offering it.
The resolution of a dash camera will affect the clarity and detail of the images. This is important when it comes to recording license plates. Having clear footage is useful especially for a hit and run where you need to identify the vehicle.
All current dash cams use an SD card to save video files. When buying a dashcam you should always buy a quality memory card that is designed to handle the heat and repeated use. Some of the popular memory cards that many people use (ourselves included) are the Samsung EVO select and high endurance cards.
Secondly, you need to consider the size of the memory card as the dash cam loop records. Essentially, it records over the older files first and that may be a short time considering a one minute 4K video clip can be 200MB or more so it easy to understand why a higher capacity card is ideal.
A 128GB SD card is the minimum you should consider with 256GB being ideal for a dual channel or 4K dash cam. The last thing you want is to loose some footage because you forgot to save it or have to fumble with the camera to lock the clip when you are driving.
Having a screen on your dash cam is a love or hate type of thing. It is useful for quick video playback and could save you some hassles. Let’s say you get stopped for speeding, you can quickly show the officer that you were not going over the speed limit and that could get you out of a ticket on the spot.
Sure, you could go to court with video evidence and plead your case, but avoiding it in the first place is a lot easier.
The other benefit of an LCD screen is being able to change the settings on the dash cam. This is easier than using an app or having to press and hold buttons.
The main drawback of dash cams with a screen is they are larger, heavier, and less discrete.
Having an LCD screen on your dash cam is not necessarily bad, it is more personal preference.
As dash cams are mounted on the windshield and constantly in the sun they can be affected by heat. This is more of an issue for people that live in hot and sunny areas like the Southern US where daytime temperatures can be well over 100 degrees and even hotter inside the vehicle. If you live in a hot climate it is recommended to pay attention to the operating range of your dash cam. For most dash cams, the operating range is between -4F and 140F.
If you park outside, it is something to keep in mind as the camera may shut off to prevent damage.
The viewing angle on a dashcam can be explained in two ways, breadth vs depth. A dash cam with a wider viewing angle will cover a wider area at the expense of depth.
However, the trade off to a wider field of view is video clarity. This makes a difference in being able to read license plates so it is something to be noted.
Most dash cams have a field of view between 120 and 160 degrees with 140 being the average. However, the processor and camera sensor will usually make a bigger difference.
Loop recording is a feature on all dash cams today. What it means is the video files constantly get overwritten starting with the oldest first. How often that happens will depend on the resolution, how many channels your dash cam has, and the size of the memory record.
This is why we recommend at an SD card of at least 128GB for a 1080P dash cam and 256GB for 4K if you drive a lot. There may be times where you want to review a video later and with a larger card you do not have to worry about marking it so the dash cam does not record over it.
This is a basic feature in all dash cams and depending on the model it will lock the video file if an impact or sudden deceleration is detected and prevent the video file from being overwritten.
If you use the parking mode, the G-sensor can detect glass breakage and activate the dash cam. If you have it connected to a WiFi network your dash cam can upload the video to a cloud and send you a notification.
Parking Mode/Motion Detection
Parking mode refers to the ability of a dash cam to record when the vehicle is parked. This is useful in a hit and run or if thieves break into your car you will have video evidence.
- Impact detection. This works as implied, basically if the dash cam detects another car hitting yours, the dash cam will begin recording. This mode is energy efficient but it may take a few seconds for the camera to become active and the vehicle that hit you may already be gone.
- Time-lapse. The dash cam shoots a still photo every second or so and if movement or an impact is detected it will activate the camera and begin recording normally.
- Motion sensor. While many dash cams offer this a feature, be sure that it is true motion sensor. True motion sensor is when the camera detects movement in its field of view. Some dash cam manufactures refers to it as detecting motion to a car if it is hit. Motion detection is great for surveilling your vehicle from suspicious activity.
- Buffered recording. In this mode, the camera is constantly recording although it does not save the footage unless an event is detected. If that happens, the previous few seconds will be saved on the memory card as well. The advantage is having evidence of the events prior to the incident but the downside to this mode is it uses a lot of energy.
Night vision refers to the dash cam’s ability to record video footage at night. Or more simply, the quality. Even for the top models, videos at night may be washed out by bright headlights which of course means license plates will be difficult to see.
Ideally, a dash cam should at least have an aperture of at least F/1.8 with F/1.6 being even better at night.
Image quality is how detailed the videos are. Of course, this will depend on the camera, resolution, and sensor but the footage should clear enough to read the license plates close up.
WDR will help brighten dark areas in the video and can be useful at night. HDR helps in bright situations and allows for more detailed images in the daytime.
The settings on each dash cam will vary by manufacturer and you may have to experiment with the settings to see what works best.
GPS in your dash cam is a useful feature that can help prove you were not speeding at the time of an alleged violation. Basically, your speed will be recorded on the video and it can be presented as evidence.
In addition, the GPS will track your location and timestamp it so you can always refer back to the data if you ever need to recall where you’ve been.
WiFi had been more exclusive to higher-end dashcams. However, it has become increasingly common on many mid-range models.
There are benefits to having WiFi on your dash cam. You can view the videos and download them to your phone without having to remove the memory card.
However, one of the biggest benefits of WiFi is it adds another level of functionality to the parking mode. A WiFi enabled dash cam can upload videos to the cloud (if equipped). You can have notifications sent to your phone and view video in real time.
Choosing an SD card is important and we recommend not going cheap. The last thing you want is to have an accident and then find the video files are corrupted. The extra money you spend on a decent quality SD card may save you big dollars later.
What size SD card do I need? At the very minimum, 64GB but ideally 128GB or 256GB. Keep in mind the size of the video files will vary depending on how many channels your dash cam has, the resolution, and video compression.
For example, a 128GB card for the BlackVue and Thinkware will hold about 6 hours of 4K video footage and the Viofo’s about half that. If you drive regularly, you will appreciate having an SD card with more memory.
What features should a dash cam have?
At the very least, a dash cam should have a G-sensor and 1080P recording with 60 frames per second (FPS) rate. This is a spec that is frequently overlooked and it makes a difference in clarity when looking at a still image of a moving object, like reading license plates. Most decent dash cams have 1080p high definition or 2K dash cams recording at 60FPS recording. For 4K 30 FPS is currently the best available.
Another consideration is getting a two-channel dashcam as a front camera will do little if you get hit from behind. They are usually not much more expensive than a 1CH model and that extra money spent may save you in the long-run.
WiFi is a popular feature in many dash cams and more models are coming with it. The main benefit is adding functionality to the parking mode. For example, you will have a backup of the video even if the thieves steal or damage your dash cam.
For ride share or taxi drivers, a 3ch dash cam may be worth the extra money for full coverage and provide extra measure of safety.