In order to choose the best CCTV Cameras you need to understand some of the basic terminology. Below is a glossary of CCTV terms to help you choose your Surveillance system and CCTV Cameras and CCTV Lenses.
Aperture: Aperture is the area of the camera lens that gathers light. The Iris of the cctv lens controls the size of aperture.
Auto Iris: Auto Iris Lenses adjust for changing light conditions in a camera view. If the sun shines on a camera with an auto iris lens, the lens will adjust the amount of light so the picture remains clear.
CCD: Charge Coupled Device - a light sensitive imaging device for almost all cameras. Typical sizes for CCTV cameras - 1/2", 1/3", 1/4".
C Mount: Type of screw-on mounting for CCTV Camera Lenses. C Mount lenses need an adapter ring when used with CS Mount camera (see CS Mount).
CS Mount: More recent type of mounting for CCTV Camera Lenses. Designed for 1/2", 1/3" 1/4" CCD cameras, CS-Mount is the more common lens mount
used today in CCTV cameras.
used today in CCTV cameras.
Day/Night Camera: A camera that is 'Day/Night' means it can capture video in both day and nighttime. In low light conditions, the Sony Day/Night chipset switches from colour to black & white at night to enhance the picture quality.
DSP: Digital Signal Processing - a technique by which video quality can be improved by adjusting parameters of the video signal.
ExView: Sony Chipset type that offers very good images in both day and night time. Typically, cameras with Ex-View chipset have good Low Light (LUX)
levels.
levels.
IR Cut Filter: An IR Cut Filter is an extra filter inside the camera that moves behind
the camera lens when it gets dark. A camera with an IR Cut Filter will produce very high quality images in low light conditions.
the camera lens when it gets dark. A camera with an IR Cut Filter will produce very high quality images in low light conditions.
Iris: Device inside a lens which opens and closes as light conditions change which adjusts the amount of light passed.
LUX: Used to specify how sensitive cameras are to light (measured in lumens/sq
metre).
e.g a camera with a LUX Level of 0 can see in pitch black. The lower the LUX Level the better the camera will see in the dark.
metre).
e.g a camera with a LUX Level of 0 can see in pitch black. The lower the LUX Level the better the camera will see in the dark.
Noise: Video Signal interference that usually appears as graininess or snow
on the picture.
on the picture.
PTZ: Pan Tilt Zoom - a camera which can be controlled via Joystick or DVR and moved up/down, left/right and zoomed in/out.
Resolution: The number of horizontal lines a system can display. Digital Resolution (e.g. 720 x 576)
720 = number of points in each row that make up the picture;
576 = number of rows.
720 = number of points in each row that make up the picture;
576 = number of rows.
Sensitivity:The sensitivity of a camera is often configured on your digital surveillance system.
Motion Detection based recording uses relies on the sensitivity of the cameras to trigger recording.
Varifocal Lens: A cctv camera lens whose focal length / viewing angle can be manually adjusted to suit the camera view required.Typical Vari Focal lens lengths are: 2.5mm-10mm, 3.5mm-8mm, 5mm-50mm.
Zoom Lens: A lens which has variable focal lengths. The image can be 'zoomed' in or out whilst the view of the camera remains in focus.
