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. |
Auto 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 impracticable 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. |
CCD (Charge Coupled Device) |
Most of our cameras are CCD in type semiconductor device that is used especially as an optical sensor and that stores charge and transfers it sequentially to an amplifier and detector |
C Mount Lens |
An industry standard for lens mounting. The C-Mount has a thread with a 1 inch diameter and 32 threads per inch. The distance from the lens mounting surface to the sensor surface is 0.69 inches (17.526 mm). It is possible to mount a C mount lens onto a CS mount camera with the use of a CS adapter ring. |
CS Mount Lens |
An industry standard for lens mounting. The CS-Mount has a thread with a 1 inch diameter and 32 threads per inch. The distance from the lens mounting surface to the sensor surface is 0.492 inches (12.5 mm). It is not possible to use a CS mount lens on a C mount camera. |
Composite |
A single video signal that contains luminance, color, and synchronization information. The American standard NTSC (525 lines, 30 frames per second) and European standard PAL (625 lines, 25 frames per second) are examples of composite video. |
Digital Recording |
The newest form of video archiving and reviewing. Digital recorders are slowly 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, CD-ROM 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 LAN, WAN, ISDN, phoneline and even the Internet. File security also eliminates image manipulation so you can be certain the video you see is authentic and unaltered. |
Federal Communications Commission (FCC) |
An independent US government agency established in 1934 and charged with regulating interstate and international communications by radio, television, wire, satellite, and cable. Any wireless equipment must be approved by the FCC in order to be used without licensing. To receive licensing information, contact the FCC by phone at 88... or on the internet athttp://www.fcc.gov/services/amateur/about |
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 1/2 horizontal lines. Adjacent lines in a TV picture (525 Lines total) are located in alternate fields. |
Infrared Lighting (IR) |
(Infrared) 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. |
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) |
LCD (Liquid Crystal Display) |
Some of our tiny monitors use LCD displays which are a constantly operating display (as of the time in a digital watch) that consists of segments of a liquid crystal whose reflectivity varies according to the voltage applied to them |
Microwave |
The portion of the electromagnetic spectrum that falls within the range of 300 MHz to 3 GHz. A very efficient transmission band for sending video signals wirelessly. Typical microwave video links use the following frequencies: 434 MHz, 900 MHz, 1.2 GHz, and 2.4 GHz. |
Monochrome |
Black and white and all shades of grey. In a monochrome video signal, this is what controls the brightness of each pixel. Since there is no color, the brightness determines what shade of gray the pixel needs to be. In a color signal, this also has control over the brightness of the pixel, whether color or not. |
Multiplexer with Multirecord Capability |
Using a multiplexer (as opposed to a quad processor), it is possible to record multiple cameras full screen with one VCR. Since every video signal is comprised of 30 frames per second, you can divide these frames among each camera. A multiplexer will send a camera’s video signal to the VCR at a consistent rate. In the example below we have 8 cameras connected to a multiplexer. Each camera is recorded evenly between 30 frames. In other words, each camera is recorded for a single frame every 8 frames or every 0.266 seconds. So when the video is played back, each camera appears as though it was recorded on it’s own time lapse recorder at 3.75 frames per second. The main advantage to multirecording is the use of a single VCR for multiple cameras. |
Quad Processor |
At one time, the only way to view and record multiple cameras on one source, you would need to use a camera switcher to automatically change between camera views. The main disadvantage of this setup was you were only capable of recording one camera view at a time. While you were viewing one camera, the others were “lost.” Now, with newer digital technology, you are able to record and view more than one camera simultaneously on one screen. The most basic of these multi-camera processors is the quad. It displays 4 cameras at a time on one screen. There are units that are capable of handling 8 or even 16 cameras, but only 4 can be displayed at a time on a single “page.” With pricing starting at under $100, it is almost unnecessary to ever use a switcher. |
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 lines that can be seen at a distance equal to the picture height. Vertical resolution is expressed as the number of horizontal lines that can be seen in the picture. |
Super HAD |
The Super HAD CCD is a version of Sony’s high performance HAD with improved sensitivity from the use of more efficient on-chip microlenses. The Super HAD optimizes the shape of the on-chip lenses in order to minimize the ineffective area between the lenses on each pixel thereby minimizing lost light and improving the overall sensitivity per pixel. |
Super Dynamic II |
This technology lets you capture richly detailed video in scenes with extremely bright and dark areas. This is accomplished with the double speed CCD that actually captures two images at different exposures. It then combines the two into one video signal that shows detail in both bright and dark areas. Compared to a regular CCD, a Super Dynamic II chip gives you 64 times the dynamic range. |
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). |
Zoom/Varifocal Lens |
A lens with an adjustable focal length. Varifocal lenses require focusing adjustments whenever the focal length is changed. Zoom lenses are described by magnification power according to the difference between the longest and shortest focal lengths. A 5mm to 50mmzoom lens has a magnification power of 10X. Also, a 10mm to 100mm zoom lens has a magnification power of 10X. Many different varieties of zoom/varifocal lenses are available including both manual and motorized versions. |
