Comparison ParkCity DVR HD 790 vs Sho-Me A7-GPS/Glonass

Model of the processor used in the dashcam

The term "video chip" is used mainly for devices with classic capabilities, "processor" — for advanced models with an abundance of non-standard functions. However, anyway, we are talking about the same component — the main computing unit, the characteristics of which directly affect the capabilities of the recorder as a whole. Knowing the model of the processor, you can find detailed data on it and evaluate how satisfied you are with a device based on such electronics. Of the most advanced modern chips, one can name, in particular, Ambarella A7L, Ambarella A12, Novatek NTK96655, Novatek NTK96660 and HiSilicon Hi3516.

The maximum resolution and frame rate of video recorded by the recorder in the HD (720p) standard.

The classic resolution for this standard is 1280x720, but there are other options in DVRs — in particular, 1280x960 (4:3 aspect ratio). Anyway, HD is not outstanding, but quite a decent indicator that allows you to get a video with good detail (for example, it is usually quite possible to make out numbers on cars in close proximity to a car on it).

As for the frame rate, the higher it is, the smoother and less blurry the video will be, the better the details on moving objects will be visible, and also the more space the footage will take up. It is worth noting here that in some inexpensive models, shooting in HD at very low speeds — 15 – 20 fps is used to reduce the cost. Such a shooting speed allows you to watch video more or less normally, but for a normal display of moving objects, a higher frame rate is still desirable — at least 25 frames / sec. It is also worth saying that, in general, for a comfortable perception by a person, a speed of 24 to 60 frames per second is considered quite sufficient, however, among the registrars there are models that can shoot HD at 120 fps. The meaning of this speed is to ensure that individual details on moving objects are as clearly visible as possible in slow motion or frame-by-frame viewing.

The maximum resolution and frame rate of video taken by the recorder in the Full HD (1080p) standard.

Many people associate the term Full HD with a resolution of 1920x1080 — and indeed, this resolution is very popular, including among DVRs. However, this standard also covers other options — in particular, 1440x1080 (4:3 aspect ratio) and 1920x540 (halved vertical size). In general, support for this resolution is a good indicator for a modern registrar, indicating that the device belongs to at least an average level.

As for the frame rate, the higher it is, the smoother and less blurry the video will be, the better the details on moving objects will be visible, and also the more space the footage will take up. It is worth noting here that in low-cost Full HD recorders, shooting can be carried out at very low speeds — 15 fps or even 10 fps. Such a shooting speed allows you to watch video more or less normally, but for a normal display of moving objects, a higher frame rate is still desirable — at least 25 frames / sec.

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 °.

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.

— 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.

— 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).

— 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 posts an...d 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.

— LDWS (lane control). A system that monitors the car's position within the lane: it monitors the car's position on the road and, if it deviates from the current lane, gives a warning signal, attracting the driver's attention. This signal can literally save the lives of road users if the driver is distracted or falls asleep at the wheel. DVRs with LDWS will be especially useful for those who have to spend a lot of time driving without a break. However, if road markings are of poor quality or absent, this function becomes useless.

— FCWS(distance control). A system that monitors the distance to the car in front and gives a signal if this distance is critically reduced and a collision is possible. Typically, FCWS is activated at a certain speed (for example, 40 km/h and above), and its sensitivity can be adjusted to suit traffic density. A collision warning is usually displayed and accompanied by an audible signal.

— LLWS(headlights reminder). A sensor that monitors the level of ambient light; When the light level decreases, LLWS reminds the driver to turn on the headlights. Such a reminder may be useful not only in the dark, but also during the day - for example, in cloudy weather or when entering a tunnel.

— Sign recognition. Intelligent system for automatic recognition and analysis of road signs. Typically..., this function aims to recognize speed limit signs and provide advance warning to the driver to adhere to the prescribed speed limits. However, many recorders with a similar function perfectly “see” other road signs, duplicating them to the driver on the screen of the head unit as a kind of safety net.

- Antison. A feature that reduces the risk of falling asleep while driving. When the Antisleep mode is turned on, the recorder, as a rule, periodically plays a special sound signal; in some models this sound stops itself, in others the driver must manually turn off the signal, confirming that he is not sleeping. However, it is worth keeping in mind that even the most advanced Antison system does not provide a complete guarantee against falling asleep while driving. Therefore, the most correct behavior when you are very tired is to stop and rest; This function should be used only in extreme cases.

The largest size of the memory card allowed for the device. This limitation is primarily due to the fact that more powerful hardware is required to work with larger volumes. In addition, there are nuances associated with individual subspecies of cards. Anyway, this value cannot be exceeded: with a high probability, the registrar will either work incorrectly, or will not be able to work at all, or even completely fail.

Most modern registrars support cards up to 32 GB or 64 GB, but there are models that are compatible with more capacious cards — 128 GB or even 256 GB.

The capacity of the internal battery installed in the device (see "Power supply").

First of all, the general purpose of the battery depends 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 backup power in case of disconnection from the cigarette lighter (for example, in an accident when the on-board network failed). In such cases, you can not pay much attention to the capacity - as a rule, it is guaranteed to be enough for at least a few minutes of offline recording, and for continuous operation the device will still have to be connected to the cigarette lighter. But for a full-fledged (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 - sometimes 200 mAh or even less is enough for them.

Note that theoretically a more capacious battery allows the device to work longer without recharging. However, in practice, comparing different models by this indicator, in fact, makes no sense: after all, the autonomy of the recorder also depends on its power consumption, and it is determined by a number of characteristics. Moreover, manufacturers sometimes select batteries of different capacities for different models just in such a way as to achieve more or less the same battery life.