Field of view
The viewing angle provided by the main camera of the DVR. As a rule, it is indicated along the diagonal of the frame, less often - horizontally, because of this, models with the same numbers in the characteristics may differ somewhat in the actual field of view. So if you have doubts about this, when choosing, it does not hurt to find and watch video samples from different models.
Other things being equal, a wider viewing angle allows you to cover more space, but individual details in the frame are smaller. In addition, wide-angle lenses give geometric distortions of the image (however, DEWARP can be provided to eliminate them, see "Functions"). As for specific figures, viewing angles
up to 120° inclusive are considered relatively small for modern registrars, values of
121 - 140 ° can be called average,
141 - 160 ° are above average, and the most wide-angle models are able to cover a space
of more than 160 °.
Screen resolution
Resolution of the display installed in the recorder.
The higher the resolution (with the same diagonal) — the clearer the image is, but the more expensive the screen itself. At the same time, high resolutions are not needed to set the camera in the desired position and to work with the basic settings of the device. So you should pay attention to this parameter only if you plan to use additional functions that require a high-quality “picture” — for example, a GPS navigator (see “Functions”) or a remote camera that plays the role of a reversing camera.
AV-output
AV output is an analogue output used to broadcast captured audio and video to an external display such as a TV. In registrars, such an output usually has the form of a mini-Jack connector, and a special cable is required for connection (often supplied in the kit, but there are exceptions). This interface does not allow working with HD resolutions, however, it does not require powerful hardware and can be provided even in the simplest and most inexpensive devices. Another advantage is that AV inputs (usually called composite) are found not only in modern, but also in frankly outdated video equipment like CRT TVs.
Battery capacity
The capacity of the device's own battery (see "Power source").
The general purpose of the battery depends primarily on this indicator. If the recorder uses a relatively modest battery, up to 500 mAh, this most often means that it plays the role of a backup power supply in case of disconnection from the cigarette lighter (for example, in an accident when the on-board mains fails). In such cases, you can not pay special attention to the capacity - it is usually guaranteed to last at least a few minutes of autonomous recording, and for continuous operation, the device will still have to be connected to the cigarette lighter. But for full (not "spare") power, much more capacious batteries are required - at least 800 mAh, and ideally 1000 mAh and higher. The exception is ultra-compact motorcycle models that do not have screens and do not consume much energy - for them, 200 mAh or even less is sometimes enough.
It should be noted that, theoretically, a more capacious battery allows the device to work longer without recharging. However, in practice, comparing different models by this indicator essentially makes no sense: after all, the autonomy of the recorder also depends on its energy consumption, and it is determined by a number of characteristics. Moreover, manufacturers sometimes select batteries of different capacities for different models precisely with the calculation to achieve more or less the same operating time on a charge.
