Installed in both businesses and households, IP cameras are designed for surveillance of indoor and outdoor spaces. Unlike CCTV, IP cameras can transmit data via a computer network and the internet.
Monochrome cameras feature improved light sensitivity, which is important when shooting in low light conditions. However, colour cameras are improving all the time and are gradually replacing black-and-white models.
The cameras can be connected to the recording unit either with wires or wirelessly. The latter option, however, means a limited transmission distance of 30-50m, which makes it a less reliable solution than wiring. Given that IP cameras continuously transmit a large amount of data, even small errors or failures can result in a substantial deterioration in the quality of recordings.
Installation is simpler than it seems and uses only standard tools for mounting devices and cables (a set of drill bits and screwdriver). It is key that the camera is mounted on a solid surface, such as a wall or ceiling.
The most widely used technology on the market, it offers reliability, easy installation and remote management. The disadvantage, however, is the low 720 × 540 resolution.
The latest technology and the successor to analogue systems, AHD offers up to Full HD resolution (1920 x 1080), providing a more detailed picture than analogue systems.
The technology allows high-resolution videos to be transmitted via a computer network. They are used, for example, on building sites, parking lots, and other such spaces.
A relatively new technology that offers simple wiring and infrastructure and image resolution up to Full HD.
Analogue cameras indicate resolution in TVL, i.e TV lines. Standard resolution is about 330 TVL, whereas quality cameras have up to 420 TVL resolution. Others camera type, i.e. AHD, IP and HD-SDI, measure resolution in pixels. The higher the resolution, the sharper the picture.
HD resolution (1280 x 720 px)
Full HD resolution (1920 x 1080 px)
Higher resolutions such as 2560 × 1920 are found in IP cameras.
Given as an f-number, where the lower the value, the better the lens. A camera with a high-quality lens can capture video even at dusk.
Different aperture types
Fixed iris - used in environments with stable levels of light
Auto iris - automatically adjusts the iris according to current light levels
There are typically two different types of image sensor.
CCD sensors - more sensitive to light, which is reflected in better image quality in low light conditions. They are used in cameras with higher resolution. The disadvantage is their higher price.
CMOS sensors - less light sensitivity than CCD sensors. On the other hand, they are less expensive to manufacture and enable the production of cameras with smaller physical dimensions.
Videos are stored on an SD card or internal memory. Motion sensors help you save storage space as the camera only records when the detectors sense movement.
Black-and-white camera - very good light sensitivity; widely used, especially in the past.
Colour cameras - worse light sensitivity in low light condition; now becoming more popular than black-and-white cameras.
Cameras are designed for either inside and outside use, with outdoor cameras being resistant to water and cold. A cameras level of resistance is indicated by an IP code, e.g. IP66, with higher numbers indicating higher durability.
Along with a zoom function, the ability of a camera to rotate up to 360° means a relatively large space can be covered by a smaller number of cameras. The angle of rotation can even be controlled remotely.
Black-and-white camaras are preferable for monitoring in low light conditions to their higher sensitivity.
Some models feature built-in IR illumination for night vision, which uses special LEDs on the infrared spectrum. The human eye cannot see the light, but it is visible to the camera sensor.
IR illumination usually activates automatically when the light level drops. It works to a distance of approx. 25 m.
CCD is a sensor type that records colour images. Image recording is performed by two methods: the location of RGB filters in front of the sensor or filters that are placed in front of the pixels in a checkerboard pattern. CCD chips can transmit information from points across rows, whereas CMOS sensors, which are structurally more complex, transmit from each point separately.
Characteristics of CCD chips
- Higher energy consumption
- Lower data processing speed
- Higher production costs
CMOS chips are often used in digital cameras. Compared with CCD sensors, they offer a cheaper alternative, with lower power consumption and faster data transfer. CMOS sensors are able to transmit data from each point separately, while CCD sensors work line by line. CMOS sensors are sometimes abbreviated as APS (Active-Pixel Sensor).
Characteristics of CMOS sensors
- Lower power consumption
- Higher data processing speed
- Lower production costs
Focus is a process that ensures the subject of a photograph appears clear and sharp. Focus can be achieved using an optical element in the lens, allowing you to focus on objects that are close or distant.
Cameras are also equipped with autofocus (AF), which adjusts the focus automatically using an electronic system. Autofocus works best for high-contrast images. The light level and movement of the subject also affects the cameras ability to focus effectively.Glossary