Most dash cams will overwrite older recordings when they run out of space. Video is saved (protected from overwriting) automatically when an incident is detected. Video is recorded, then immediately overwritten at a specified interval unless saved. Continuous loop recording to minimize storage requirements.Don’t avoid 4K UHD-which is a feature in our best overall picks-but read the reviews first so you know whether the cost is justified. For most purposes,1080p is the more frugal everyday choice. In our tests, the gain in detail from 4K video (2160p) can vary, but the storage investment is consistently heavy: four times the storage of 1080p, or around 1GB for every three minutes of video. Do you need 4K UHD? It’s easy to fall victim to the specsmanship of a higher-res image.WDR (wide dynamic range) is much like above, except it usually refers to only color and not contrast.

It also generally indicates richer color. HDR (high dynamic range) isn’t necessary, but it does make for more detailed video because of better contrast.Infrared lighting is important if you want to assure good captures of nocturnal events inside the cabin of your vehicle.Day and night video recording (night quality is a big variant).Note that the wider the field of view, the more fish-eye distortion there is, and more processing is involved to compensate. Some cameras offer 160- to 180-degree lenses. A decently wide field of view: You’ll see cameras with as little as 90-degrees field of view, but you’ll catch more of what’s around you if you go for 120 to 140 degrees.Interior cameras are generally situated on the dash cam, but rear cameras are separate and require additional cabling. Dual-channel support: This is what you’ll need if you want to run both front and rear, or interior (cabin-view) cameras.We’ll step you through what to think about when you’re shopping for a dash cam, from video capabilities, recording options, power connections, and more.

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