Screen type
The sensor is a key element of any digital camera; it is from it and from signal processing technologies that the quality of the resulting image primarily depends. In this case, the type refers rather to the brand or brand of the matrix; it is usually indicated if the recorder is equipped with a high-quality sensor that is noticeably superior to most solutions on the market.
One of the most popular such options is
Sony. The specific characteristics of the matrices (
IMX179,
IMX222,
IMX291,
IMX307,
IMX317,
IMX322,
IMX323,
IMX326,
IMX335,
IMX415) may vary, but anyway, such a sensor is a sign of a high-end DVR.
In addition, there are models equipped with matrices from other manufacturers —
Aptina,
OmniVision,
Samsung(GalaxyCore),
Sandvik. Such solutions are generally considered to be simpler and more democratic than Sony — both in terms of price and functionality. Nevertheless, Samsung has a lot of developments in the field of electronics, and even such r
...elatively “simple” sensors are usually more advanced and of higher quality than “know-names”.
Another manufacturer that produces fairly high-quality matrices is Panasonic. Such sensors are not as widespread as those described above, but they are still found in video recorders, including pretty advanced.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.
Recording features
Among the photo and video functions used in the dashcam, we can distinguish
G-sensor,
rotating lens,
live,
HDR< /a>, WDR,
polarizing filter,
DEWARP and
Time Lapse. More about them:
— G-sensor (video saving). A sensor that monitors shocks and vibrations acting on the DVR. The main function of this sensor is to ensure the safety of video materials in the event of an accident: in the event of a strong impact, characteristic of a collision or fall, the recorder with a G-sensor automatically saves the previously recorded video to a non-volatile memory protected from overwriting. Thus, materials about an emergency are not only guaranteed to be saved, but with a high probability remain intact even if the recorder itself is damaged. In addition, the G-sensor is used in
parking mode — see "Functions" for details.
— Swivel lens. The ability to rotate the lens of the registrar horizontally or vertically, and in some cases — on both planes. This feature allows you to adjust the camera's field of view.
— Sound recording. Ability to record sound with a video recorder. First of all, we are talking about recording conversations in the cabin, which can become an add
...itional argument in disputable situations — for example, they will allow you to determine whether the driver was talking on a mobile phone at the time of an accident, whether he noticed the situation on the road, how he assessed it, etc.
— Live broadcast. Allows you to remotely connect to the DVR and monitor what is happening from the camera in real time. It is very important if there is an additional camera in the cabin, when you can track the situation, for example, in taxi services, courier delivery, etc. This function will also become important and useful when a car is stolen, when you can not only see the hijacker from the video from the camera, but also track the route of his movement.
— HDR (high dynamic range). A function that increases the dynamic range of the recorder. Dynamic range is the maximum difference between the brightest and darkest area achievable within a single frame. Initially, this range for digital matrices is small, so an image with large brightness differences (for example, a road against a sunset sky) turns out to be either strongly overexposed in bright areas or very dim in dark areas. HDR addresses this shortcoming and also improves the overall colour quality. This is implemented as follows: the camera takes several frames with different settings and from them forms the finished image. At the same time, this technology is simpler and cheaper to implement than WDR, which is similar in purpose (see below). The main disadvantage of HDR is that this type of shooting increases the blurring of fast moving objects in the frame somewhat.
— WDR (Wide Dynamic Range). A function similar in purpose to HDR described above: it is used to improve the quality of a “picture” that has strong differences in brightness. The key difference between these technologies is that WDR works at the hardware level — due to high-end matrices. This allows you to achieve the required dynamic range within a single frame and do without gluing several frames — as a result, WDR, unlike HDR, does not give a blurring effect and does not worsen the detail of moving objects in the frame. The downside of this quality is the high price.
— Polarizing filter. The presence of a polarizing filter in the main camera of the DVR. Such a filter reduces the brightness of glare arising from strong light on glass, water and other similar surfaces. This greatly improves image quality, especially when shooting in sunny weather.
— DEWARP. A technology used to correct the "picture" obtained using a wide-angle lens. Such lenses are often used in DVRs; one of their drawbacks is their propensity for the fish-eye effect, the characteristic distortion when straight lines in the frame turn into rounded ones. The DEWARP function eliminates this shortcoming — it "bends back" curved lines, correcting the geometry of objects in the frame. Note that such a correction does not always work 100% accurately, however, the picture processed by DEWARP is anyway more reliable than without this technology.
— Time Lapse. A special mode of operation in which video recording is carried out at a slow frequency, which in practice is mainly used for shooting slow processes. Thus, for example, a long journey or a long sunset can fit into a 3-minute video.External camera
One or more remote cameras in the standard equipment of the registrar, used for video recording of the traffic situation behind the car. In the vast majority of cases, the remote camera is attached to the DVR in
one copy. It covers the rear "stern" of the car and is simultaneously used as an assistant when reversing parking — the picture from the camera can be displayed on the DVR screen in real time. There can be
several remote cameras, which provides a wider coverage of the DVR's field of view.
Video resolution
The maximum video resolution supported by the optional DVR camera. Depending on the design and configuration, we can talk about both a remote camera and a camera for filming the interior (see above for both); this nuance should be clarified separately.
The higher the resolution, the more detailed the image from the camera will be, the more small details will be normally visible on it. On the other hand, high detailing affects the volume of materials to be filmed and the requirements for the “hardware” of the registrar (and, accordingly, affects the cost).
In general, additional cameras of modern recorders can be divided into the following categories:
— SD. "Standard" resolution (as opposed to HD — "high resolution"). A rather modest frame size, which at the same time allows you to significantly save memory for video recording and is suitable even for low-cost recorders. Specific resolution options include, but are not limited to, 628x582, 640x480, and 720x480.
— HD 720p. The traditional, most popular resolution for this video recording standard is 1280x720. In addition to it, registrars also found 960x720 (aspect ratio 4:3) and reduced in height 1280x480. HD is the most modest of today's high-definition standards, but still provides pretty decent detail.
— Full HD 1080p. The "classic of the genre" for this standard is the resolution of 1920x1080, however, there are other values in registrars, including very speci...fic ones — such as 1440x1080 (4:3 aspect ratio) and 1920x540 (halved vertical resolution). This is a fairly solid indicator even for the main camera of the registrar, and there is no need to talk about additional ones.
— Super HD. Not a particularly popular standard in video technology, which, nevertheless, has found application in video recorders. Most often provides a resolution of 2304x1296, which provides even more
Frame frequency
Maximum video frame rate supported by the optional DVR camera. Depending on the design and configuration, we can talk about both a remote camera and a camera for filming the interior (see above for both); this nuance should be clarified separately. Anyway, it is with this frequency that the shooting is carried out by default.
The higher the frame rate, the clearer the moving objects will be on the video, the less they will be blurred and the less “jerky” the video itself will be. It is believed that the most comfortable for the human eye is a speed of 24 to 60 frames per second; a lower frequency is already perceived as a “slideshow”, and a higher one only increases the amount of material being shot, without giving a visible increase in quality. At the same time, registrar cameras can also provide higher filming speeds than 60 fps — this provides good visibility of individual moving parts in slow motion or frame-by-frame playback.
Viewing angle
Viewing angle of the additional dashcam camera. Depending on the design and configuration, it may refer to either an external camera or an interior camera (see above for both); this nuance should be clarified separately. The viewing angle can be specified both horizontally and diagonally, which is why models with the same figures in the specifications may slightly differ in their actual field of view. However, in this case, this difference is not critical.
In theory, a wider viewing angle allows for capturing a larger area, but individual details in the frame become smaller. Additionally, wide-angle lenses can cause geometric distortions at the edges of the image; the DEWARP technology (see "Features") used to eliminate them is usually not used in additional cameras.
