Resolution of IP camera
The higher the resolution of the IP-camera matrix, the better the quality and detail of the image (which is especially noticeable when zooming in on the monitor). Often 2 megapixel (Full HD) resolution, supported by most modern monitors, is sufficient.
The most common resolution is:
HD (720p) – 1280×720 (1 MP) – medium resolution, suitable for general assessment of the surveillance area.
SXGA (960p) – 1280×960 (1.3 MP) – increased number of pixels vertically for a specific, stretched-up scene.
Full HD (1080p) – 1920×1080 (2 MP) – human-identifiable resolution.
Quad HD (1440p) – 2560×1440 (4MP) – improved detail with medium bandwidth requirements.
5MP – 2560×1920 (5MP) – high detail, crisp picture.
4K UHD or Ultra HD (2160p) – 3840×2160 (8 MP) – excellent image quality, fine detail detection, the ability to use digital zoom.
With the development of digital technology, the tendency to increase the number of effective pixels is increasing, although high resolution is only relevant at sites where you need to clearly see the value and number of the bill, recognize the license plate at a great distance, constantly zooming the picture.
IP-camera lenses
Structurally, the lens is a complex system of lenses, enclosed in a frame and mutually compensating optical distortions. It collects and projects light energy onto a light-sensitive matrix to form an optical image.
The main parameter is the focal length (measured in millimeters), which determines the angle of view and the scale of the image. It is the distance from the axis of the lens set to the focal point (the intersection point of the originally parallel rays after passing through the lens). The smaller the focal length, the larger the field of view. A 2.8 mm lens provides video surveillance in a sector with a viewing angle of ~100º. The higher the focus of the camera (e.g. 8 mm), the smaller the angle of view, but the greater the required distance to the observed object for quality photography.
Video surveillance systems have different tasks, so IP cameras use short-focus, long-focus and ultra-long-focus lenses of different types: fixed focal length, variable focal length, motorized and fisheye.
Fixed focal length lenses
Focal lengths are set at the factory and remain constant throughout use.
Variable focal length lenses
These lenses have focal lengths set from short to long (2.7 ~ 13.5 for example) – they can be changed. IP camera with such optics is much easier to install, an order of magnitude more places for installation.
Motorized lens is equipped with an actuator (usually servo) – for remote control of focus and zoom. Often the motor-zoom includes an optical stabilization system, focusing and iris. IP-camera with zoom are in demand at high-security sites with a need to scale the image almost instantly (zoom rate not exceeding 5 seconds).
Fisheye
Fisheye lenses are very wide-angle (up to 180°), which is why the raw image is characterized by a distorted display of straight lines in the form of arched curves. Fisheye-equipped camera images are divided into separate channels by software (built-in IP camera or separately purchased software), correcting distortion at the same time. Fisheye camera replaces several conventional cameras.
IP Camera Form Factor
IP-cameras are available in dome, cylindrical, standard design (box), cube, spherical form factors.
Dome IP cameras are the most popular. Designed for horizontal (ceiling) mounting, but special brackets allow installation on a vertical plane.
Cylindrical IP-cameras are installed on a swivel bracket. Adjustment is used to set the direction of view. IP-camera bullet is often performed in dust-and-moisture-proof and vandal-proof housing, with a visor protecting from direct jets of water and sunlight, with a wide range of operating temperatures. Typically mounted on a vertical surface: wall, pole, fence.
Body cameras or cameras of standard design are mainly produced without a lens and mounting bracket, leaving the installer a wide choice of installation and equipment of the device, which increases the flexibility of configuration and expands the scope of the model. Built-in thermal housing adapts the camera to outdoor conditions.
IP-camera form factor Cube is designed for indoor use, equipped with a bracket for mounting on the ceiling, wall, table (desktop mounting is most popular).
Sphere – a form factor that determines the direction of IP-camera surveillance: the ball is simply rotated to the desired side – there is no dome, it is not necessary to remove it. A special screen is provided to protect the lens.
A separate group of IP cameras are rotary cameras. They support PTZ technology, use special software and drives to rotate and tilt the body for maximum level of control and coverage of a larger surveillance area. IP pan-tilt cameras with autotracking and motion detection independently follow the object of observation throughout the monitored area.
There are also highly specialized models that do not fit into any of the standard form factors, such as remote lenses (for retail).
Design of IP Cameras
IP cameras are produced for indoor, outdoor and transport applications.
Outdoor IP cameras meet specific requirements:
Compliance of the enclosure with the International Protection Marking (IP) for dust and moisture protection. The first number is protection against foreign objects (dust), the second – against the penetration of water. IP cameras for outdoor use must have an IP54 ~ IP68 rating.
Operating temperature range (provided that the enclosure meets the IP54 ~ IP68 protection standard). At minus 10 ° C – the camera can be installed in unheated rooms, at minus 20 ° C – outdoors in southern regions of Russia and the CIS, at minus 40 ° C – almost anywhere, and at minus 60 ° C – outdoors even in areas of the Far North (in such IP-cameras have protection against corrosion and icing).
Outdoor IP cameras
Transport IP cameras are specialized equipment, protected from vibration, equipped with special reliable connectors (usually threaded M12). Each transport IP camera is subject to mandatory conformity certification.
IP cameras for transport
Regardless of the purpose, for installation in places that are not in sight of security guards, IP-cameras are produced, protected from mechanical influences of varying degrees – the body corresponds to the international classification code IK08 ~ IK10.