Hackett Security Security FAQ
- What is UL (2050 or 681)???
- What is Access Control?
- What is an automatic iris lens?
- What is Aperture?
- What is Back Light Correction (BLC)?
- What is Camera Format?
- What is CCTV?
- What is the CP-01 Standard?
- What is Depth Of Field?
- What is a Digital Video Recorder?
- What is Focal Length?
- What is Infrared Lighting?
- What is a Field?
- What is LUX?
- What is Resolution?
- What is a Varifocal Lens?
- What is White Balance?
ANSWERS
- UL Certification
Two standards are maintained by UL for this category:
• UL 2050, the Standard for Safety of National Industrial Security Systems, establishes a variety of ways in which installation, monitoring, investigation and repair service can be provided.
• UL 681, the Standard for Safety of Installation and Classification of Burglar Alarm and Holdup Alarm Systems, further defines requirements for installation of equipment and devices comprising an alarm installation in a protected area.
An alarm system certificate ties them together through the Alarm System Certification process; certificates are issued by UL at the request of UL Listed alarm service companies. The use of certification for compliance with the National Industrial Security System Category has increased steadily since its establishment in 1992.
Top - ACCESS CONTROL
A set of procedures performed by hardware, software and administrators to monitor access, identify users requesting access, record access attempts, and grant or deny access to a specific area.
Top - APERTURE
In CCTV optics, the aperture is the diameter of the lens that controls the amount of light reaching the image sensor. It is shown by an f-number. Larger aperture lenses have smaller f-numbers. For instance, a lens with an f-number of 1.2 will allow more light to reach the sensor than a lens with an f-number of 2.0 thus producing a brighter image.
Top - AUTOMATIC IRIS LENS
An automatic iris lens is a lens with a motorized iris that automatically adjusts to only allow a specific amount of light to reach the image sensor. When there is little light, the iris will open to let more light in. When there is too much light, the iris will close to reduce the amount of light let in. Auto iris lenses are primarily used in applications where light levels vary and it would be impractical to manually adjust the lens. Automatic iris lenses are generally more efficient than the electronic shutter since they actually control the amount of light reaching the sensor as opposed to simply adjusting shutter speed.
Top - BACK LIGHT CORRECTION (BLC)
Many Supercircuit cameras include a BLC circuit. This circuit is used to help correct an image with more light behind the subject being viewed. Without backlight compensation, the subject appears dark with little detail. Using the backlight compensation will reduce the brightness of the light to allow the subject to appear brighter and bring out the details.
Top - CAMERA FORMAT
Refers to the size of the imaging sensor. Common formats are ¼”, ½”, 1/3”, 2/3”, and 1”. The size of the sensor directly affects the field of view obtained. When using the same size lens on different format sensors, different viewing areas are obtained. For example, using a 6mm lens on a 1/3” sensor will give you a 37degree field of view the 56 degree and 74 degree on a 2/3” sensor. It is important to make sure you have a lens that was designed for your camera’s format. The lens must be designed for at least the size of your sensor. For instance, you can use a 1” camera. If you use a lens designed for a smaller format camera, the image will be vignetted. Also, by using a lens designed for a larger format sensor, the field of view you get will be greater than what is specified.
Top - CCTV
CCTV is the common abbreviation for Closed Circuit Television.
Top - CP-01 Standard
CP-01 is a standard initiated by the Security Industry Association for security system control panels and their associated arming and disarming devices to reduce the incidence of false alarms.
Top - DEPTH OF FIELD
For a lens, the area along the line of sight in which objects are in reasonable focus. It is measured from the distance behind an object to the distance in front of the object when the viewing lens shows the object to be in focus. Depth of field increases with smaller lens aperture (higher f-number), shorter focal lengths, and greater distance from the lens.
Top - DIGITAL VIDEO RECORDER
The newest form of video archiving and reviewing. Digital recorders are quickly replacing time lapse recorders as the number one storage media. Digital recording takes advantage of the speed and reliability of PC hard drives and other computer storage devices such as high speed DAT media, CDRW and even compact flash media. Storage using these devices virtually eliminates video degradation and tape wear. Digital recording also opens up almost limitless remote viewing possibilities using standard transmission modes such as phone line, ISDN, Cable, DSL, T1, LAN, WAN, etc. File security also eliminates image manipulation so you can be certain the video you see is authentic and unaltered.
Top - FOCAL LENGTH
The distance from the lens to the surface of the imaging sensor when the subject is focused. Expressed in millimeters. Shorter focal lengths give wider field of view. Longer focal lengths give narrow (telephoto) views.
Top - INFRARED LIGHTING (IR)
The area below the visible spectrum. B&W cameras are very sensitive to infrared light and allow the use of infrared illuminators to enhance poorly lit locations without alerting subjects during surveillance. Color cameras are also sensitive to infrared light, but require an infrared filter to filter out the red light to keep the image colors looking natural.
Top - FIELD
One of the two equal parts into which a television frame is divided in an interlaced system of scanning. There are 60 fields per second in the NTSC system. The NTSC field contains 262 ½ horizontal lines. Adjacent lines in a TV picture (525 Lines total) are located in alternate fields.
Top - LUX
A unit measuring the intensity of light. Full moon light is about 0.1 lux whereas full daylight is about 10,000 lux. Most color cameras can produce decent images during deep twilight. Most black and white cameras need about as much light as produced by a full moon. With our new HAD and Super HAD CCD cameras, the only light you need is starlight on a dark night. (about 0.0003 lux)
Top - RESOLUTION
The amount of resolvable detail in a picture, or the maximum number of pixels that can be distinguished either horizontally or vertically. Horizontal resolution is expressed as the number of distinct vertical resolution is expressed as the number of horizontal lines that can be seen in the picture.
Top - VARIFOCAL LENS
A lens with an adjustable focal length. Varifocal lenses require focusing adjustments whenever the focal length is changed. They are described by magnification power according to the difference between the longest and shortest focal lengths. A 5mm to 50mm zoom lens has a magnification power of 10X. Also, a 10mm zoom lens has a magnification power of 10X. Many different varieties of varifocal lenses are available including both manual and motorized versions.
Top - WHITE BALANCE
Color cameras only. Different lighting sources provide different color temperatures. The white balance helps correct these differences by adjusting the color processing to bring the color temperature to a fixed level. Without this balancing feature, due to the CCD’s poor adaptability, some colors would appear different (green instead of white in sunlight.)
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