Used for flush mount camera. Since it allows to monitor the subject through a small hole whose diameter is less diameter of the entrance pupil of the lens. Detect such a camera to the naked eye, especially when concealed under her furnishings, is difficult. Zoom lenses. This is a lens with variable focal Proximity to help you manage larger image of 6, 10 or 14 times, which allows to get high quality images of distant objects or fine detail. It is particularly convenient use in conjunction with turning the zoom device (see below), since it allows not only to monitor the movement of the object of observation, but also consider the interesting parts (face, car number, etc.) The management of such lenses is done by remote devices.

Multi-focused lenses. This is a fixed lens, focal length, which can be adjusted manually. The basis of any camera system is based on the television camera. When choosing a camera must be considered:> Full color or monochrome (black and white). Price cameras, providing a color image, is already so low that, given the cost of the entire system, it is advisable to always use only these types.

However, there are certain operational requirements when necessary to use monochrome cameras that perform certain functions under certain conditions, with higher the efficiency, so, it is believed these cameras provide users with more useful images in low-light Coy. Format. Typically, the following format: 1/3-inch (1 inch = 2.54 cm), 1/2-inch, and 2/3-dyuymo-vye one-inch, these figures relate to the size of the sensor light beam defined by the second chamber, which receives the focused light reflected from the subject. Format of the lens and the camera must match. What format is more, the better the camera, other things being equal. Sensitivity. Manufacturers of such equipment is usually expressed as a product of this figure 'suites' ('Luxury' – a unit of measurement of luminous flux) by a factor F.