Explanation of common terminology associated with camera systems.
Alarm Input: Many security camera’s and DVR’s have an input for a sensor such as a motion detector that will trigger the camera or system to begin recording. This is done to cut down on the amount of recording storage needed as well as make it easier to find events in the recordings.
Analog Security Camera System: A system where cameras create analog video signals and sends it over coaxial cable to a DVR or camera hub. The advantages of an analog camera system vs a an IP or digital system are ease of implementation, lower cost and greater cabling distance (without a repeater
BNC Connector: This is a connector for coaxial cable and that has male and female twist lock type connections. It is the most common type of connector for security camera systems.
Bullet Camera: Is a type of security camera that is cylindrical in nature and is often used for outdoor applications. Bullet cameras are available in analog and IP versions as well as a variety of camera technologies and specifications,
CCTV: Is an acronym for Closed Circuit Television. This basically means it is a video system designed for a limited number of people to view and is not broadcast (like a TV station).
Compression: In terms of video compression is the technique of taking a video signal (analog or digital) and restructuring the data so it “takes up less space” and therefore takes up less resources for storage and transmission.
RG59: This is a type of coaxial cable that is commonly used for analog camera system implementations. It is a bit smaller than RG6 coaxial cable which is commonly used for television distributions.
Dome Camera: These are camera’s that are mounted in a half spherical dome, and are often used in ceiling mount applications. They are available in analog and digital versions as well as variety of different camera technologies.
Digital Video Recorder (aka DVR): Is a device that serves as the brains of an analog security camera system. It records the video signals from the connected cameras into storage which is usually a hard drive. It is also responsible for playback and other intelligent features such as remote access.
Focal Length: This is defined as the distance from the center of the lens to the camera’s CCD measurement. This measurement is relevant because it determines the field of view of the camera. You want a camera that has a correct focal length for your application. Short focal lengths provide a wider angle of view and are suited for viewing closer objects and longer focal lengths have a narrower field of view and are suited for objects at a distance.
FPS (Frames Per Second): Sometimes also referred to as the frame rate, it is the rate of images a camera (or DVR during playback) can display in one second. Excluding other variables, the higher the FPS the more fluid the video.
Housing: Refers to the case or covering of a camera to protect it from weather elements.
Infrared (IR) Camera’s: this refers to security cameras that have infrared LED’s to provide an image in low light or night conditions. Although infrared light is not in the visible spectrum, the camera coverts or shifts the infrared illuminated environment to the visual spectrum. This technology is starting to be overtaken by intensifier camera technology.
Intensifier Camera’s: This is a camera technology for low light or night conditions that essentially amplifies light and allows for color night time images and a greater range than infrared cameras.
IP Camera System: Refers to a camera system that utilizes an Ethernet network for data and communications. The advantages of IP camera system include higher video resolutions and the ability to utilize existing network cabling infrastructure.
LUX : Refers to a measure of intensity of light. A low Lux rating for a camera essentially means it requires less light to capture a good image. Camera with infrared or intensifier technologies usually have very low LUX ratings.
Network Video Recorder (NVR): Is a software program that is usually used for the recording, viewing and controlling an IP Camera system.
Power Over Ethernet (POE): Is a standardized method to transmit power for a security camera on the same network cabling that transmits the data. This can be an advantageous implementation for IP camera systems as a local power source for each camera is not required. POE requires a POE network switch.
Power Supply: This is a device that is used to provide power to the cameras in an analog camera system. The most common power supply’s for analog camera systems are 12v DC and 24v AC.
PTZ (Pan/Tilt/Zoom) Camera: This refers to a camera where a user is able to remotely control the pointing and zooming of the camera.
Remote Access: Refers to the ability of camera system to let authorized users log into the system and view live or recorded video over a network or internet. Many Nextec customers view their camera systems from anywhere in the world using a computer, smartphone’s such as an iPhone or tablets such as an iPad.
Siamese Cable: Refers to cabling commonly used in analog camera systems that has both a coaxial cable for video transmission and a power cable for powering the camera itself.
Signal to Noise Ratio (S/N Ratio): This is a specification that refers to much noise in the video signal a camera can tolerate and still provide a good image. A higher number is preferable.
Smart Search: This refers to the ability of video recorders to search for changes in a certain area of an image over time. For example, if you just wanted to see when people entered a door, with smart search you could draw a virtual box around the door and then search the recording for changes to the area.
Varifocal Lens: This refers to a type of lens that has the capability to change the focal length. This allows adjustment of the magnification and field of view of the security camera.