Number of LEDs
The number of backlight LEDs (see "Design and capabilities") provided in the camera design.
Theoretically, more LEDs provide more power and, accordingly, range (see below) and efficiency
of IR illumination or LED illumination. However, in fact, such light sources can vary markedly in performance; in addition, a lot also depends on the features of the camera itself. Therefore, in fact, this indicator is a reference, and when choosing, it makes sense to pay attention to parameters that are closer to practice — in particular, the same backlight range (see below).
Illumination range
Operating range of the backlight (see "Design and capabilities") installed in the surveillance camera. This term usually means the maximum distance from the camera to the observed object, at which it is able to provide a relatively high-quality and legible image in the complete absence of other light sources. Of course, the actual backlight range may differ from the claimed one, and these differences are most often in the direction of increase (for example, due to the presence of the same additional light sources). However, if the possibility of shooting with backlight is important for you, you should focus on the claimed range.
Maximum humidity
The highest relative humidity at which the camera is able to operate normally, without failures and breakdowns, for an unlimited time.
Modern electronics tolerate low humidity well, but high rates affect it negatively — with a long stay in such an atmosphere, moisture can condense on certain parts of the structure and various unpleasant consequences, from corrosion to short circuits and fires. Therefore, you can use the camera effectively and safely only in conditions where the humidity does not exceed the maximum recommended value specified in the specifications. At the same time, we note that many devices are able to endure short-term (up to several hours) exposure to high humidity without consequences.
Material
The main material used in the construction of the camera body.
— Plastic. Inexpensive and at the same time quite practical material. Plastic is light, quite strong (not as strong as metal, but still quite sufficient for most cases), chemically inert (and therefore not susceptible to corrosion and insensitive to moisture), and also has a relatively low thermal conductivity (which provides additional protection for extreme temperature fluctuations). Due to all this, this material is very popular in indoor chambers (see "Usage"). At the same time, it is somewhat less suitable for outdoor work.
— Metal. The main advantage of metal, in comparison with plastic, in the case of surveillance cameras is high strength and reliability. This allows you to use it even for street models that work in difficult conditions and must have a certain anti-vandal resistance (at least not immediately “give up” when trying to break or break). At the same time, such material is much more expensive, and therefore less common.
