Glossary
Short explanations of video surveillance and security system terms: WDR, PoE, H.265+, IP67 and more.
77 terms
Image
- 3D DNR3D DNR: digital noise reduction; a cleaner image in low light.
- ApertureAperture (F): how much light the lens lets through; a small number lets in more light.
- BLCBLC: brightens a dark subject against backlight, e.g. a person standing in a doorway.
- ColorVuColorVu: colour images even in total darkness, using a constant light source.
- Colour technologyColour technology: the approach to colour images in low light (ColorVu, Starlight).
- Day/night modeDay/night mode: the camera switches to night vision automatically in low light.
- DefogDefog: reduces the effect of fog and haze, improving the view in bad weather.
- DWDRDigital WDR: balances bright and dark areas in software, a lighter form of WDR.
- EISEIS: electronic image stabilisation; reduces shake from vibration.
- Field of viewField of view: how wide an area the camera covers in one frame.
- FPSFrames per second: the higher it is, the smoother the motion in the video.
- Frame rateFrames per second (fps): the higher it is, the smoother the motion in the video.
- HLCHLC: masks very bright sources, e.g. car headlights, so the rest stays visible.
- Image sensorImage sensor: the chip that turns light into an image; its size affects quality.
- IRInfrared illumination: night vision in the dark with light invisible to the eye.
- IR rangeIR range (m): how many metres the infrared light reaches in the dark.
- LuxLux: the unit of illumination; the lower it is, the darker the scene the camera can see.
- Maximum resolutionMaximum resolution: the largest image size the camera produces.
- MegapixelsResolution in megapixels: more pixels, more detail in the image.
- Minimum illuminationMinimum illumination (lux): the lowest light at which the camera still sees.
- ResolutionResolution: the number of pixels in the image; more pixels mean more detail.
- ROIROI: region of interest; the chosen area is recorded in high quality, the rest in lower.
- Smart IRSmart IR: automatically adjusts the infrared light so nearby objects are not overexposed.
- StarlightStarlight: a high-sensitivity sensor for colour images in low light.
- WDRWide dynamic range: balances very bright and dark areas in one frame.
- WDR dBWDR strength in decibels; the higher it is, the better it balances contrast.
Lens
- Focal lengthFocal length (mm): a small number gives a wide view, a large one a narrow, distant view.
- Lens mountLens mount: the standard that attaches the lens to the camera.
- Lens typeLens type: fixed, varifocal or motorised lens.
- Optical zoomOptical zoom: the lens really magnifies without losing detail.
- PTZPTZ: a controllable camera that pans, tilts and zooms.
Network and power
- BitrateBitrate: the video stream rate; a higher bitrate means more detail and more traffic.
- dBidBi: the unit of antenna gain; more dBi means a longer coverage range.
- ePoEePoE: extended PoE; power and data up to 300 m over one cable.
- Network interfaceNetwork interface: a wired (RJ45) or wireless connection for data.
- ONVIFONVIF: an open standard that makes cameras and recorders from different makers work together.
- P2PP2P: easy connection; remote access to the camera without complex network setup.
- PoEPower over Ethernet: the camera gets power and sends data over one network cable.
- PoE+PoE+ (802.3at): higher-power Power over Ethernet; for heated and PTZ cameras.
- PoE portsPoE ports: how many cameras the recorder/switch powers directly over the Ethernet cable.
- RJ45RJ45: the standard Ethernet network port.
- Wi-FiWi-Fi: connects to a wireless network without a network cable.
Recording and storage
- Drive baysDrive bays: how many hard drives fit in the recorder.
- DVRDVR: a video recorder for analogue/HD-TVI cameras.
- H.264H.264 (AVC): a widely compatible video compression standard.
- H.265H.265 (HEVC) compression: the same quality as H.264 with almost half the storage and traffic.
- H.265+H.265+: an improved H.265 that saves even more disk space and bandwidth.
- microSDmicroSD card: local recording right in the camera, without a recorder.
- Number of channelsNumber of channels: how many cameras the recorder (NVR/DVR) connects.
- NVRNVR: a network video recorder for IP cameras.
- Recording compressionRecording compression: the format the recorder stores video in.
- Storage supportStorage support: the hard drive or microSD card type and maximum capacity.
- Video compressionVideo compression: the codec (H.264/H.265) that reduces the video size.
- Video outputVideo output: the port for connecting a monitor (HDMI, VGA).
Analytics
- AcuSenseAcuSense: recognises people and vehicles to cut false alarms.
- Motion detectionMotion detection: the camera reacts to motion in the frame and starts recording or an alarm.
- SMDSMD: smart motion detection; reacts to people and vehicles, ignores trees and rain.
- SMD PlusSMD Plus: improved smart detection; recognises only people and vehicles to cut false alarms.
- VCAVCA: smart video analytics; recognises line crossing, zone entry and similar events.
Analogue signal
- AHDAHD: an HD analogue video standard over coaxial cable, compatible with DVRs.
- BNCBNC: a coaxial video connector for analogue cameras.
- CVBSCVBS: the standard analogue video signal (SD quality).
- HD-CVIHD-CVI: an analogue standard for HD video over coaxial cable.
- HD-TVIHD-TVI: HD video over coaxial cable; an upgrade path for analogue systems.
Housing and protection
- Alarm inputAlarm input: ports for external sensors (door contacts, motion detectors); their signal starts recording or a notification.
- Alarm outputAlarm output: a relay that switches on a siren, a light or a door lock when an alarm goes off.
- AudioAudio: the camera or recorder records sound too, not just images.
- Form factorHousing type: the shape of the device (dome, bullet, turret).
- IK10IK10: a vandal-resistant housing that withstands strong impacts.
- IP65IP65: a housing protected from dust and rain, for outdoor mounting.
- IP66IP66: protected from dust and strong water jets; for outdoor mounting.
- IP67IP67: full protection from dust and water; for outdoor conditions.
- IP ratingIP rating: the degree of dust and water protection; a high number suits outdoor mounting.
- Operating temperatureOperating temperature (°C): the range in which the device works safely.
- Power consumptionPower consumption in watts: how much power the device draws.
- Power supplyPower supply: how the device is powered (12V DC, PoE or 220V).
- Two-way audioTwo-way audio: a built-in microphone and speaker; listen and talk through the camera.