Aperture
The aperture ratio of the lens installed in the video recorder.
This parameter determines how much the optics weaken the transmitted light flux. The aperture ratio is indicated by a fraction - for example, f/1.8. The smaller the number in the denominator, the more light the lens can transmit. A conventional model with an f/2.2 lens will theoretically produce a darker image than a recorder with a high-aperture optics of f/1.5.
High aperture ratio is important, first of all, when shooting in low ambient light conditions: it allows you to capture images in the twilight and dark hours of the day without creating additional artifacts in the form of noise. At the same time, when shooting with high-aperture optics, the blurring effect of moving objects in the frame is reduced. On the other hand, the actual quality of the recorder camera depends on many other factors - in particular, the type of matrix, the image processor used, etc. Therefore, the aperture ratio specified in the characteristics is not the ultimate truth - it is rather for reference.
Navigation
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Speed on video. The ability to display data on the current speed of the car on the video being shot - usually in the form of numbers in one of the corners of the frame. As a rule, the device receives speed information from the built-in GPS sensor (see below). This function can be especially useful when analyzing ambiguous situations - for example, as additional evidence that the driver did not violate the speed limit.
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GPS module. Built-in GPS satellite navigation module, which allows you to determine the current coordinates of the device. The specific ways in which this information can be used may vary depending on the other functionality of the registrar. Thus, it is data from GPS that is used to display speed on video (see above), as well as for the operation of the GPS informer and
GPS navigator described below. There are other options, sometimes quite original - for example, if you have
a 3G/4G modem, a beacon mode may be provided (
GPS tracker - see below).
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GPS informant. A function that provides the driver with various useful information related to the current location. As the name suggests, the location itself is determined using GPS. One of the most popular ways to use an informant is to warn of approaching traffic cameras, stationary post
...s and speed control systems that are not detected by a traditional radar detector. In addition, other similar functions may be provided - for example, a message about an area with a high accident rate or a separate large hole on the road. To operate the GPS informer, a database of relevant objects is entered into the device’s memory; When purchasing, it doesn’t hurt to clarify what exactly this database contains, how fresh it is, and whether it allows for updating and manually adding points.
— GPS navigator. The device can operate as a full-fledged GPS navigator. For this, in addition to the GPS module itself, the design provides built-in maps, as well as a fairly large display to display them. This allows you to do without purchasing and using a separate navigator, but this function is not particularly popular in modern DVRs. Firstly, it significantly affects the cost of the device; secondly, a regular smartphone or tablet with GPS is often enough to navigate on public roads; thirdly, recorders most often have rather modest navigation capabilities and are often inferior even to smartphones/tablets, not to mention specialized devices.
— GPS tracker. Another function found in recorders with a GPS module (see above). A GPS tracker allows the device to operate in beacon mode, constantly transmitting data about the location of the car to one or another recipient - for example, taxi service dispatchers, the customer of cargo transportation, etc. Such beacons are also sold as separate devices, but it is easier (and sometimes cheaper) to buy and install a recorder with this function. In any case, it is worth considering that a 3G/4G modem is usually used to transfer data (see below) - so to use the tracker you will have to buy a SIM card and regularly pay for mobile communications.
— GLONASS. The device supports the GLONASS navigation system, the Russian analogue of the GPS described above. Most often, this function is provided in addition to the GPS module: simultaneous use of two systems improves the speed and accuracy of positioning, and also provides an additional guarantee in case of failures in one of them.
—Galileo. European satellite navigation system, created as an alternative to American GPS. Note that it is under the control of civilian departments, not the military. With a full fleet of 24 active satellites, the system provides an accuracy of up to 1 m in public mode and up to 20 cm with the GHA service. Working in conjunction with GPS, Galileo provides more accurate position measurements, especially in densely populated areas.
