Comparison GT C25 PAL vs Tiger TG-CM28

The physical size of the photosensitive element of a camera. It is usually measured diagonally and is indicated in inches — more precisely, fractional parts of an inch. The larger the sensor, the larger the size of each individual dot (pixel) on it, the more light enters each pixel, and the easier it is to ensure high image quality with a minimum of noise (especially when it comes to shooting at dusk). However you need to remember that only matrices of the same type and resolution can be compared with each other in size. And a large sensor is not always a guarantee of quality — a lot depends on the rest of the hardware of the camera, the quality of its installation and other factors. However, the large size of the sensor usually indicates a high class camera.

The resolution of the frame taken by the camera in video mode, in pixels — in other words, the size of the picture in dots horizontally (first digit) and vertically (second digit). It should be taken into account here that in the case of reversing cameras, the recording in pixels describes only the frame on the camera matrix itself; to describe the "picture" coming to the connected screen, the designation in television lines (TVL) is used. This is due to the fact that the video signal is transmitted in an analogue format; See Video Resolution below for more on all of this. Here we note that with the same resolution in TVL and the same viewing angles, a camera with a higher resolution in pixels will produce a clearer, more detailed image. But HD reversing cameras, and even more so Full HD units.

Although modern electronics are dominated by digital standards, car reversing cameras still use an analogue signal transmission format. This is due to compatibility requirements: such video allows you to use fairly simple screens. And although its quality loses to digital, it is quite enough for most of the tasks facing this class of auto electronics.

An analogue video signal has a size in horizontal and vertical dots. But since the number of vertical dots has a strictly defined number of 625 (in the PAL and NTSC colour system), resolution is usually indicated only by the number of horizontal dots (TV lines).

In fact, this parameter describes the quality of the image that is displayed directly on the screen connected to the camera. There are models with a value of 480, 500, 520, 540, 560 TVL and even higher resolution in TVL. This is important for models with wide viewing angles (see below). On the other hand, in order to use all the features of a camera with numerous TV lines, a screen corresponding to these features is also required; For more details on compatibility with the screen, see specialized sources.

The viewing angle characterizes how wide the area of space is captured by the camera lens: the larger they are, the wider the field of view, the more space is in the frame. In most modern models, it varies from 120° to 170°; this allows good visibility of almost the entire rear hemisphere. There are 180° cameras and even more; they will come in handy if visibility is important to you not only from behind, but also on the sides. But note that some manufacturers indicate the angle horizontally, while others — diagonally.

At the same time, it does not always make sense to chase wide angles. Note that the larger the viewing angle, the more distant, reduced the image looks, the more distortion occurs at its edges. In addition, wide viewing angles require high resolution, which accordingly affects the price of the camera; if the resolution is low, the "picture" may look blurry and small details will be lost on it.

The colour system refers to the format in which colour information is transmitted in an analogue video signal. In modern reversing cameras, the European PAL system or the American NTSC are most often used. It makes no sense to describe them in detail — suffice it to say that for the normal operation of the camera you need a radio tape recorder (or other device with a screen on which the image is displayed) with support for the same colour system. However, incompatibility in this parameter is not fatal — with such a connection, the image will only turn from colour to black and white (in extreme cases, its overall quality will slightly deteriorate).

This parameter describes the total amount of interference in the video output from the camera. The higher the signal-to-noise ratio (that is, the ratio of the useful signal level to the level of extraneous interference) — the better the image will be, the less distortion it will have. The minimum level for modern cameras is considered to be 40 dB — with it, the “picture” is reproduced with minor noise that does not significantly affect its perception. And in the most advanced models, this figure can reach 48 – 50 dB — such an image for the human eye is almost indistinguishable from the perfect one.

Of course, in fact, the quality of the image also depends on the capabilities of the screen on which it is displayed, however, even the best screen will not save a “noisy” camera.

The lowest ambient light level at which the camera can provide a normal image without additional illumination. In modern models, this indicator varies on average from 0.01 lux (clear night at a quarter moon) to 3 lux (deep twilight).

The lower the minimum illumination, the better the device handles with low light. However, note that in the absolute majority of cases, car cameras at night are used together with car lighting devices: front ones (see "View type") — with main headlights, rear ones — with reversing lights. Therefore, this parameter is rather general reference or even advertising information, rather than a really significant characteristic.

The format for displaying the image on the connected screen. For each type of review (see above), there is a different option that is optimal.

— Direct. The traditional way of displaying an image: the user sees on the screen the same thing that the camera lens "sees" in front of him, with the same arrangement of the details of the situation. Simply put, if some object is located to the left of the centre of the camera's field of view, it will also be visible on the screen on the left side. All front view cameras work this way.

— Mirror. In this mode, an image is displayed on the screen that is “mirrored” horizontally — roughly speaking, one in which “left” and “right” are reversed: an object to the left of the camera lens will be visible on the right side of the screen, and vice versa. All cameras with a rear view type work in a similar way. This is due to the fact that in an ordinary rear-view mirror the driver sees exactly the picture inverted horizontally; therefore, in order for the sides of the picture on the screen to correspond to the usual view in the mirror, the image coming from the camera has to be “mirrored”.

— Direct / mirror. Cameras capable of operating in any of the picture modes described above. Usually, these are universal models (see “Installation”), which formally refer to the rear view type in our catalog (see above), but also allow front view.