One of the most important parameters when choosing a DVR is the way of attaching it. The stronger it is, the less chance that critical moment, the device will detach itself from the glass. In the usual models used two ways of fastening: on the suction Cup and double adhesive tape. The suction Cup is less reliable, since the changes in temperature and humidity can easily fall off and over time the mount weakens.
In addition to the method of fastening, must pay attention to the optical part of the recorder. It needs to have a sufficiently large angle from 90 to 140 degrees to capture several lanes in front of the car. It is desirable that the resolution of the recorded video was as much as possible, this is one of the most important characteristics affecting the quality of the picture. Best of all, if will start recording in HD 1280x720.
You must also pay attention to the frequency of the recording. It should be no lower than 25 fps. at the nominal resolution of the instrument. Very handy when the recorder has several modes recording speed, i.e. on the Parking it removes, for example, 10K/sec. but the motion – 25K/sec. This makes it possible to achieve significant savings of space on the memory card.
Another characteristic of the DVR is the maximum memory card capacity that it can support. Than this value the better. Also a very important video format. This is usually MPEG4 or H. 264. The last one is preferable because each frame in this format takes 2 times less space. In addition, you must choose a DVR with a large matrix size. Have good devices with HD recording it is usually 1/2 or 1/1.8 inch.
A very important characteristic that people should pay attention when choosing the DVR, is the climatic version. In conditions of Russian winter, it is necessary that the device can withstand the temperature drop to -30, and it is better to -40 degrees.
It is also desirable that the DVR has the following additional features: - built-in monitor;
- auto start/off video recording when you start/stop of the engine;
-fixing the time, date;
- sound recording.
More expensive models can be equipped with a GPS receiver for determining coordinates of the vehicle via the satellite, as well as mode night mode with IR illumination. GPS allows you to view the vehicle's route on the map.
Only well-chosen device can provide high-quality video, which really can become evidence in a dispute. Therefore, it is better not to save on the DVR, because the cheap device is simply a pointless purchase, which can be very expensive in the future.