Dash cam specifications include numbers for picture detail, viewing width and driver-assist functions. Here is what each one means.
Resolution
Resolution is the number of pixels in each video frame. More pixels allow finer detail, such as number plates and road signs, particularly when you crop or zoom a recording.
- 1080p (Full HD): 1920 by 1080 pixels. A standard entry level and adequate for general recording.
- 1440p (2K or 2.5K): a sharper picture that improves plate readability at a distance.
- 4K: 3840 by 2160 pixels. The most detail, with larger files that need a bigger memory card.
Resolution is not the only factor. The sensor, the lens quality and the handling of low light all affect how legible a recording is, especially at night. Look for mentions of night vision, HDR or WDR, which balance bright and dark areas, such as headlights against a dark road. Frame rate matters too: 30 frames per second is typical, and 60 gives smoother motion.
Field of view
Field of view (FOV) is the angle the lens covers, in degrees. A wider angle captures more lanes and the roadside, but objects appear smaller and edges can look distorted.
- About 110 to 130 degrees: a balance of coverage and detail.
- About 140 to 170 degrees: captures neighbouring lanes and junction activity, with some loss of fine detail in the centre.
ADAS
ADAS stands for advanced driver-assistance system. On a dash cam it means software alerts based on the camera image, such as a lane departure warning, a forward collision warning, and a reminder when the car ahead has moved off. These are advisory aids only. They can make mistakes with faded road markings, poor weather or unusual road layouts, and they do not replace attention to the road. They need the camera to be mounted level and calibrated as the manual describes.
Other useful features
- GPS: adds location and speed to the footage.
- Wi-Fi: lets you view and copy clips to a phone.
- G-sensor: locks a clip when it senses an impact so it is not overwritten.
- Parking mode: records when the car is stationary; it usually needs a hardwire kit or a battery pack.
- Front and rear: a second camera covers the back window.
- Memory card: choose a card rated for continuous video recording and check the maximum size the camera supports.
Rules on dash cam use and on sharing footage vary by country, so check the local requirements.