PTZ Cameras

Rotary camera, also called a PTZ camera , is a video monitoring device with the possibility of rotation in the vertical and horizontal axes. Thanks to the movable head, the device has the ability to observe a much larger area. These cameras were very often used in monitoring public utility facilities, including offices, schools, but also in prisons, banks or large parking lots. For over a year, PTZ cameras have been gaining more and more popularity among individual customers who use them to monitor their home, company or plot. In this article, we will describe the basic parameters that are worth paying attention to before deciding to buy this type of camera. Contrary to appearances, this is not an easy decision because external PTZ cameras can be found on the Internet at prices from PLN 150 to even PLN 50,000.

Cameras can be divided into rotary and high-speed cameras. As you can guess, the first ones are much slower than the second ones, so they will be better for monitoring a further area to keep up with moving objects. The rotation speed of the camera depends on the quality of the components used in it. In high-speed models, the components used allow for smooth, fast and reliable rotation even hundreds of thousands of times a day.

Depending on the model, we distinguish devices that have a specific range of rotation (e.g. in the case of Zintronic P5, it is 320* in the horizontal axis and 90* in the vertical axis) or have no limit and can rotate around. Cameras that rotate around their own axis seem to be more practical, because we can direct it to the area of interest faster.

PTZ cameras distinguish two basic types of image zoom: digital zoom, i.e. enlargement of the image read directly by the matrix using software (with increasing zoom, the image loses quality) and optical zoom in which, by changing the focal length, we can enlarge the image without any loss on quality. Depending on the mounted lens, the camera has a certain magnification multiple (e.g. times 4).

We must remember that the optical zoom can only be used in real time, i.e. when we are watching the live image from the camera. This is possible thanks to the optical mechanism installed in the device. Only digital zoom works on saved recordings. It is very important to ask the seller before making a purchase whether the offered camera is equipped with a digital or optical one. Optical zoom will always make the camera more expensive by up to several hundred zlotys than a full-focus camera with digital zoom, even though the parameters of both devices will not differ in anything else.

Very often, PTZ cameras have a patrol function, i.e. automatic movement along a pre-programmed route. The device must be specially adapted to work in this mode. Currently, on the Internet you can find a lot of offers of cameras with a patrol function, even for about PLN 200 or less. So let's think about whether the camera for such a low price can actually be adapted to such work? For example, let's set 4 patrol points in the camera. At each point, the camera will stop for 2 to 5 seconds. A device with such a programmed sequence will make about 6,000 revolutions a day. This gives us about 180,000 turnover per month, which is over 2,000,000 per year. Components in PTZ cameras below PLN 1,000 are not adapted to such intensive work. Our tests show that these types of cameras with continuous patrol function last about 2 months, after which they start to stop spontaneously and do not always respond to the rotation command. These disadvantages do not occur in professional speed dome cameras, for which, unfortunately, we will have to pay from about PLN 2,000.

To compensate for the lack of a patrol function in PTZ cameras, manufacturers have introduced an object tracking function. After detecting a person, the camera follows their movement until they leave the frame, and then returns to the previously set place. This feature can be found in the P5, P5 PRO or P5 Ultimate camera series. It is much more effective than the standard motion detection resulting from the change of pixels in the image, thanks to generating a negligible number of false alarms.

In most cases, CCTV cameras are equipped with infrared LEDs and an infrared filter. These elements allow us to record the image even in complete darkness. We distinguish lighting with different power, which translates into the distance of the illuminated area. The P5 camera has illumination up to 40M, and the P5 PRO camera, through the use of stronger diodes, can illuminate the area up to 50M. Please note that the quality of lighting depends on the correct installation of the camera and the environment. Each object can negatively affect the illumination, e.g. by covering the infrared stream or reflecting it straight into the camera's eye, which results in overexposure of the image. Infrared is best illuminated in an open area, where there is a lot of greenery (grass, bushes).