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AC refers to alternating current electricity. 110 volts AC is the type of electricity most often found in home and office electrical outlets in the United States. Outside the U.S. many countries have standard outlet voltage of 220 ~ 240 volts AC. In addition, many CCTV products use 24 volts AC, for which a separate power transformer is required.

 

AC/DC refers to changing between alternating current (AC) and direct current (DC). Switching from AC power from your home or office outlet to DC current is required for most of our products. A transformer can easily be used to regulate the current; for this reason, we include AC/DC power supplies with almost all of our products. There are also power inverters which convert DC current to AC current. Such power inverters are commonly used to power 110 volt AC devices (such as a VCR video recorder) from a DC automotive or marine battery.

Alarm/Event Operation is a feature found in many CCTV video recording devices like VCRs and DVRs. This allows the user to interface alarm sensors (like a PIR motion detector) with the recording device through an alarm in/out port (this port has a physical electrical contact). An alarm/event capable recorder can then be set to automatically start and stop recording when the alarm is triggered (such as by motion). However, the digital revolution is replacing the need for bulky and expensive alarm sensors. Many newer digital DVR recorders feature advanced video motion detection, which can provide dynamic motion detection recording with built-in software alone.

Alarm Input Some cameras and video servers have the ability to accept alarm inputs. These are inputs from standard sensor devices such as, Passive Infra-red (PIR) detectors, door contacts, active beams etc. or relay outputs from intruder alarm panels, or access control panels. Alarm input circuits can come in a number of forms. Most commonly they are self powered, so will operate with a passive switch style circuit. However, in some cases, they expect to be provided with power (normally 12V) as the signal of open or closed. In a few cases manufactures only supply TTL (very low voltage) level inputs. In that case, they can only be safely used with normal alarm sensors in conjunction with some additional isolation circuitry. In this case, it is best to contact the manufacturer for advice.

Alkaline Battery - This is a type of battery most commonly found at retailers around the world. Alkaline batteries are suggested to power all video equipment using the mobile BAT-1, BAT-3, or BAT-AAA battery packs. For some products (those with input voltage as low as 9.6 volts DC), however, rechargeable Nickel-Metal-Hydride batteries may also be used. In addition, using lead acid, lithium-ion, or lithium polymer batteries may also provide adequate power for video cameras and other devices so long as the +/- polarity is correct and the batterys output voltage falls within the devices safe operating range.

Amps (A) are used to measure electrical current consumption. 1 amp (A) = 1000 milliamps (mA).

Amplifier typically refers to a device which adds strength to a signal for a better and / or longer performance ability. Amplifiers can be found for both wired and wireless equipment. A VDA (video distribution amplifier) is designed to extend a video signal through wires by boosting the power of the video signal. Transmitter-end and receiver-end amplifiers can be found for wireless equipment to help increase broadcast range potential.

Analogue Continuously variable numerical values such as voltage, current, etc. (The CCD camera produces analogue video signals.)

Angle of View the scene angle that a video camera lens can show on the monitor, like Diagonal Angle, Horizontal Angle and Vertical Angle, usually described in degree.

Antenna Element - Antennas for wireless equipment are constructed of elements which are specifically tuned to a given frequency or range of frequency to improve gain.

Antenna Gain refers to any increase or decrease in the strength of a wireless RF radio frequency signal when considering external antenna equipment. Gain is typically measured in terms of decibels (dB) or a number of times of magnification.

Antenna Type refers to the design of a particular antenna. Common antenna types for wireless CCTV are dipole whip antenna (the most common), yagi, flat panel, omni-directional, parabolic dish, and heliophase.

Aperture The light gathering area of a lens, controlled by the iris.

ARP Address Resolution Protocol; for mapping an IP address to a physical machine address.

Aspherical Lens A lens designed with a non spherical shape so that it passes more lights or decreases barrel distortion on wide angle lenses.

Aspect Ratio is a specification for monitors. This term refers to the ratio between the width and height of a video image. Typically, CCTV cameras produce an aspect ratio of 4:3 (the vertical size of the picture is 75% of the horizontal width). This is the same ratio for compatibility with standard consumer televisions and video equipment as well as security-industry monitors and video recorders. Widescreen televisions, on the other hand, have a 16:9 aspect ratio. Attenuation A decrease or loss in a signal, usually measured in decibels.

Audio indicates sound. When audio is listed as a feature of some video product, this usually means one of a few things: a device for monitoring sound (microphone), a wireless transmitters ability to broadcast sound, or a video recorders ability to record audio.

Audio Input Plug refers to the type of connector plug for a devices audio input jack. In most cases, this is a standard RCA connector or 1/8" (3.5mm) mini plug.

Audio Input Type - There are two basic kinds of audio found for video equipment connections: line-level and mic-level. Line-level indicates that the audio input device (like a microphone) must be preamplified in order to record or broadcast the audio signal. All wireless products, recorders, and monitors require line-level microphone connections. For compatibilitys sake, all microphones found on this site are line-level and contain preamplifiers.

Auto electronic shutter (AES) Feature of a camera to adjust for light changes without the use of an auto-iris lens.

Audio Output Plug refers to the type of connector plug for a devices audio output. In most cases, this is a standard RCA connector or 1/8" (3.5mm) mini plug.

Audio Output Type - Audio output for a device can be either line-level or mic-level (see note above in audio input type). So long as the audio output is line-level, there is no need for mic-level connections. Video recorders and monitors typically have line-level inputs, making connections simple.

Auto Iris (AI) Cameras with an Auto Iris feature, have the ability to compensate for large variations in light levels. Particularly useful for cameras that need to compensate for changes from bright sunlight to dark shadows. The auto iris circuitry is normally linked to a motorised iris drive that physically opens and shuts the iris on the lens. Closing a physical iris is a much better way to protect a camera from being damaged by bright sunlight then simply using electronics to reduce the signal strength. A diaphragm device in the lens that adjusts to light level changes. The iris diaphragm opens or closes the aperture to control the amount of lights coming through the lens.

Auto-focus Lens automatically adjusts the lens focus from surrounding scene and keeps a moving object in focus.

Automatic Gain Control (AGC)  refers to a circuit within the camera which regulates image brightness levels for optimum performance and highest video quality. This is a feature of many CCTV cameras that helps keep the strength of the output signal constant, even when the light level changes. In other words, it boosts the signal strength at low light levels, and caps it at higher levels.

Auto Homing An automatic sequential video switcher which has manual switches or buttons, which allow a single CCTV camera to be displayed on screen without sequential switching.

Automatic Level Control (ALC) Allows the auto-iris circuitry to either take bright spots more into consideration (peak), bringing out detail in bright areas, or less into consideration (average) bringing out detail in shadows.

Automatic Light Control (ALC) is a built-in feature of every camera found on Eyespyvideo.com. ALC indicates the image sensors ability to automatically adjust in diverse lighting conditions to yield the most vivid video image possible.

Auto-Iris Lens is a lens with a built-in method of automatically controlling the lens aperture for the best video quality under diverse and changing lighting conditions. Auto-iris lenses can be especially helpful under very low light and bright direct forward light. In order to use an auto-iris lens, however, the video camera you are using must have a built-in auto-iris port to supply the lens with a small amount of DC electrical voltage. Manual iris lenses are also available and do not require any special ports or cable connections.

Auto Terminating Automatically select the correct termination depending on whether the video output is connected.

Back Focus is the alignment of the rear of the lens to the imaging device.

Back Light Compensation is a feature of cameras that automatically adjusts the image to compensate for bright sunlight or bright lights, to give more detail on the darker areas of the image. For example to focus on the detail of a face of a person that has the sunlight shining from behind. BLC indicates the image sensors ability to automatically adjust in conditions where lighting is from behind the camera to deliver the sharpest and highest quality video image possible.

Balanced Signal is a method of transmitting audio or video signals over a pair of wires, often twisted pair cable. By sending two equal, but opposite signals, this system minimises external interference, and maintains signal quality.

Balun stands for Balanced - Unbalanced. It is a device used to interface between balanced lines and unbalanced lines. For example, twisted pair to co-axial.

Bandwidth indicates the complete range of frequencies over which a circuit or electronic system can function with minimal signal loss. In effect, bandwidth indicates the amount of information and its complexity which can be carried over a signal. More complex information requires more bandwidth for an effpixels signal. (i.e. color video bandwidth > monochrome video bandwidth > bandwidth for one channel of audio). The capacity of the transmission medium stated in bits per second or as a frequency. Or, the amount of data that can be transmitted in a fixed amount of time. For digital devices, the bandwidth is usually expressed in bits per second (bps) or bytes per second. For analogue devices, the bandwidth is expressed in cycles per second, or Hertz (Hz).

Battery refers to a stored power device. For mobile and remote applications, one or more batteries can be used.

Battery Run Time indicates the amount of time a piece of electronic equipment can realistically be powered using a particular battery pack. For instance, the CC-1HAD color board camera has a battery run time of about 24 hours when using eight fresh "AA" alkaline batteries in our BAT-1 or BAT-3 battery packs. More battery time could potentially be obtained with a higher capacity battery. It must also be noted that the more power consumption load on a battery or battery pack.

Baud A unit of measurement that denotes the number of bits that can be transmitted per second. For example, if a modem is rated at 9600 baud it is capable of transmitting data at a rate of 9600 bits per second.

Bit Abbreviated with small "b".  Binary Digit. The smallest unit of data in a computer.

Black & White (monochrome) Camera - Cameras are available with either color or monochrome image sensors. Monochrome cameras are typically referred to as black and white because video image they produce is in shades of gray. Only black and white CCD cameras have the ability to utilize IR infrared lighting. Also, even without infrared lighting, a monochrome camera will generally perform better in low light conditions than will a color camera equipped with a comparable CCD imager, lens, and quality of manufacture. The black and white cameras deliver amazingly crisp video, and in fact much better than the human eye when only a tiny amount of light is available.

Blanking the process whereby the beam in a CRT is cut off during the retrace period.

Blooming The defocusing of regions of the picture where the brightness is at an excessive level, due to enlargement of spot size and halation of the fluorescent screen of the CCTV monitor

BNC Bayonet Neil-Concelman or British Naval Connector BNC is the type of connector plug commonly found on CCTV devices for video and audio input / output connections. BNC is the choice for broadcast video and security video professionals because of its locking design. BNC plugs are easily adapted to standard consumer RCA connectors using a simple one-piece plug adapter. Nearly all products include the necessary adapters so that users can select either BNC or RCA connections to suit their individual requirements for immediate plug and play use. A connector widely used in the CCTV industry, usually for coaxial cable. Easy to install and reliable with little video signal loss.

Bps Bits per Second is the unit used for measuring line speed, the number of information units transmitted per second.

Brightness Control The manual bias control on a cathode ray tube or other display device that controls the average brightness and the contrast of a picture. Brightness Control is a feature found on many monitors. It allows the user to manually select the level of screen backlighting (brightness).

Bridging term used to describe a type of automatic sequential switcher which has the ability to send a signal to two monitors (dual output) - one continually sequencing and the second one able to display any one of the CCTV camera inputs on the "bridged" monitor.

Bullet Camera - A bullet design refers to a camera with a cylindrical shape using an inline video imaging chip (rather than a board design). These cameras are sometimes also called "lipstick cameras" or "inline CCD cameras."

Burned-In Image An image which persists in a fixed position in the output signal of a CCTV camera tube after the camera has been turned to a different scene or, on a CCTV monitor screen.

Byte  

Abbreviated with capital "B". A unit of data that is eight bits long and is used by most computers to represent a character such as a letter, number or symbol.\

Camera format Video cameras CCD chips format; 2/3", 1/3", 1/4", etc. Camera Sensor: Video image sensor. CCD or C-MOS chip.

C-/CS-Mount Lenses and Cameras- The security industry has agreed upon a standard size lens mounting thread and coupling diameter with C and CS mount lenses. Cameras built with this type of lens mount can easily be configured with any of a large variety of C and CS mount lenses available for CCTV. Although C and CS are not exactly the same size, most cameras designed for this type of lens can accept either configuration using a simple plastic adapter. These lenses are standardized and will always thread properly, but exchanging C and CS mount lenses does require back focusing. This process requires the user / installer to slowly find the exact right thread position of the lens to ensure a clear video image. An industry standard for lens mounting. C-Mount is 1-inch diameter with 32 threads per inch. A C-Mount lens needs a C-ring when it is mounted on a CS-Mount camera. The C mount lens has a flange back distance of 17.5mm. The CS mount lens has a flange back distance of 12.5mm. C mount lenses therefore have a longer focal distance. CS mount became widely used, because it its more practical for many of todays more compact cameras. Lenses are often supplied with a 5mm spacer ring (sometimes called a C ring) that allows a C mount lens to be used on a CS camera. Most modern cameras are CS.

CCD stands for charged coupled device. This is a solid-state semiconductor element which uses hundreds of thousands of tiny pixel elements to accept light and translate that information into a vivid, visible picture image. A CCD is one type of camera image sensor. CCDs produce MUCH higher tvres, lower light sensitivity, and better overall video quality than CMOS imagers (also commonly found in CCTV industry cameras). One of the two main types of image sensing device used in cameras. It operates by converting light energy into electrical charge.

CCIR is the standard monochrome video format used in most of Europe, Israel, and some other places in the world. CCIR products are also generally referred to as PAL because all PAL products can also handle black and white CCIR video. Some camera models available on atss.in are also available in PAL / CCIR video format for foreign clients and special applications.

CCTMA Closed Circuit Television Manufacturers Association.

CCTV stands for closed circuit television: a video system which will only be monitored in a closed environment (as opposed to public broadcast). The realm of video security and surveillance is also referred to as CCTV. CCTV Is a Television system that sends a signal to one or more monitors rather than broadcasting over a public network, hence closed-circuit. A standard CCTV system will normally include a CCTV camera (for capturing video), transmitters and receivers (to transfer the video from the source to where it is recorded), a recording system (for video playback), and a monitor (for video monitoring). CCTV systems are primarily used for security purposes inside and outside buildings. However, they can also be used for specialist applications such as mobile police use and interrogation.

Chrominance  refers to the part of the video signal that contains the colour information.

CMOS stands for charged metal oxide semiconductor. This is one type of camera image sensor which uses a charged metal surface to detect light and create a video image. CMOS technology is often smaller than CCD chips are currently capable of, so these cameras can often be quite miniature. While very low quality CMOS cameras are available for as little as $10 or $20, even the highest tvres CMOS cameras cannot compete with newer CCD imagers in the important fields of tvres, sharpness, and low light performance.

Coaxial Cable is the most common type of cable used for transmitting a video signal through copper wire. This type of wiring has a coaxial cross-section where an outer shielding protects the actual interior signal conductor from electromagnetic interference. In the CCTV industry, the term "coax" usually refers to RG-59 cable with BNC-type plug ends.

Codec refers to an internal computer component which processes analog information (like a video or audio signal) into a digital format such as MJPEG, MPEG-4, Wavelet, etc. for electronic storage on digital recording media. Without a codec in place to compress and digitize video, digital video recording to a hard disk drive would not be possible.

Color Camera - Cameras are available with either color or monochrome image sensors. Color cameras produce video images bearing the entire visible spectrum of colors. And because color CCD cameras have come a long way in recent years, the colors of objects appear vivid, crisp, and distinguished on monitoring and playback of video. The color cameras deliver amazingly crisp video, and in many cases better than the human eye when only a small amount of light is available.

Colour Saturation the degree of mixture of a colour and white. High saturation means little or no white.

Composite Video is the standard type of analog video signal utilized by most CCTV video cameras. This signal is plug and play compatible with most consumer television and VCR equipment. However, this type of video should not be confused with digital "component" inputs which may ALSO found on newer televisions and other home video equipment. A composite video signal has the correct phase rate, luminance, and chrominance information to be compatible with a particular video format such as NTSC, PAL, EIA, CCIR, etc. A full video signal that combines picture signal and synchronisation pulses.

Compression Digital video pictures can be compressed with a number of techniques. These include: JPEG and JPEG-2000 (for still images), M-JPEG and MPEG (for moving pictures).

Compression Method refers to the computer software technique the codec in a DVR video recorder (or DVR card) uses to convert the video signal to digital information so it can be compressed and stored on digital media like a hard disk drive, DVD, or CD. Uncompressed video would require massive processing power and nearly unlimited storage capacity and is, therefore, completely out of the question in the real world. MPEG (M-JPEG) and Wavelet are the most common types of compressed digital video, but there are variants of these in addition to other proprietary formats. MPEG-1 and MPEG-2 typically offer the highest quality recording (DVDs use MPEG-2), but smaller file sizes can be obtained by using a lower tvres, more efficient compression method like Wavelet or MPEG-4. It should also be noted that the method of compression a video codec uses to compress and digitize video information may NOT always indicate the video file type / extension for playback. Instead, the final digital video format available from a DVR recorder on backup (via USB, CD or DVD burner, etc.) could be in AVI format or even a proprietary format despite MPEG compression.

Contrast The noticeable difference between blacks and whites in a picture. If the two extremes look like gray and off-white the contrast is not good. A gray scale can be used to check the CCTV monitors ability to reproduce good contrast.

Contrast Control is a feature of many video monitors. This allows the user to manually adjust the screen contrast for better picture visibility.

Contrast Ratio is a monitor specification. This number indicates the dynamic range of brightness (difference between darkest and brightest) a monitor is capable of displaying.

CRT Cathode Ray Tube. The vacuum tube part of a monitor or television.

Current Delivery indicates the amount of electrical current (usually measured in milliamps, amps, or watts) available from some device which has output voltage (like an AC/DC power transformer or a battery pack). Current delivery describes the amount of "juice" a power supply or other product which outputs voltage can deliver to another product in need of electrical power.

Current Draw indicates the amount of electrical current (measured typically in milliamps or amps) required to safely and effpixelsly power a device.

Decoder A device used to recover the component signals from an encoded source.

Decibel (db)  is a logarithmic scale. In the context of CCTV it refers to voltage or signal strength. A 6db increase is equivalent to doubling the signal strength.

Depth of Field (also known as depth of focus) refers to the range of distance from the camera that is in good focus. The smaller the aperture of the lens, the longer the depth of field. However, less light coming into the lens, means that the image will be dimmer, so the camera needs to compensate by increasing the gain. For example, the best (longest) depth of field would be obtained on a bright, sunny day, with a very small aperture on the camera. In this case the imaging device still gets a reasonable amount of light, even with a small aperture. The worst (shortest) depth of field would be in a dark room, with a large aperture. To improve depth of field, the best approach is to increase the amount of light on the subject, or use a more sensitive camera.

Digital indicates information which is encoded into ones and zeros (binary code) by some computer processing element. Digital in this industry, however, can refer to several different things. Digital signal processing is a feature of all Eyespyvideo.com CCD cameras and many multiple camera processors. Digital video refers to digital recording of video using a DVR video recorder or DVR card.

Digital Signal Processing (DSP) is a level of image correction or enhancement which takes place within a device using a digital computer element. This digital element encodes the information into digital information for the highest level of detail and quality. Cameras with DSP imagers do not necessarily produce "digital video," but they do provide very crisp video images. Quads and multiplexers offering DSP do not necessarily produce "digital video" either, but they do deliver very high tvres and often other dynamic characteristics.

Digital Video (DV) refers to video which has been compressed into digital information for storage onto digital storage media like a hard disk drive, CD, or DVD. The quality of digital video will vary depending on factors such as the camera quality and compression method.

Digital Video Recorder (DVR) - This device is capable of accepting one or more video (and sometimes audio) input signals for recording onto digital storage media. A DVR is basically a computer specifically designed to gather and compress video into a digital video format for storage on a hard disk drive or other form of digital media. DVRs are quickly replacing VCR video recorders for security and surveillance purposes without the need for changing tapes. Key differences between DVR and VCR recorders come to available features. Advanced DVRs are capable of accepting multiple video and / audio inputs without the need for bulky and expensive multiplexers or video quads. As well, most DVRs offer built-in motion detection recording (without costly and conspicuous PIR motion sensors), and many can be remotely viewed and played back over the internet. Some models may easily be backed up onto external media for long term archival. These backup methods may include CDs, DVDs, flash media cards, or via USB to a computer or other storage device. Eyespyvideo.com offers several DVR models, all selected for their superior reliability, ease of use, quality of manufacture and variety of useful features. This is a device that records video signal digitally. Normally this is on a large hard drive in the machine. For this reason it is sometimes known as a hard disk recorder (HDR). Digital Video Recorder records video pictures digitally.

DIP Switches Dual Interface Poll switches usually allow you to change the configuration of a circuit board to suit your application.

Directional Antenna - An antenna for wireless equipment which sends or receives a propugated radio signal on the same axis as the corresponding antenna on the other end (with line-of-sight visibility between the two whenever possible). While omni-directional antennas are great for short range broadcasts because of their versatility, high gain directional antennas are recommended for most long range wireless video applications.

Distribution Amplifier A device that provides several isolated outputs from one looping or bridging input, and has a sufficiently high input burden and input-to-output isolation to prevent loading of the input source.

DSL Digital Subscriber Line. A technology for bringing higher-bandwidth information to homes and businesses over ordinary copper telephone lines.

Digital Versatile Disk (DVD) Sometimes called digital video disk. This is an optical disk the same size as a CD, used for storing data of various formats. Including video, audio and computer data.

Direct Drive (DD) Some auto iris lenses require a DC signal from the camera. These are known as direct drive lenses.

Distribution Amplifier  is a device that accepts one video input and sends it out to 2 or more devices. This is often used in a situation where the signal needs to be split between a number of video monitors or recording devices. 2 or 3 devices can often (but not always) be driven just by splitting the signal with a "T" connector, but more than that, and invariably a distribution amplifier is required to give an acceptable signal quality.

Duplex An electronic device used to record and display camera images at the same time. A full-duplex DVR can record camera images while displaying images from a different camera at the same time.

DVR Card - A DVR card is a device for installation in a home PC computer which converts that PC into a DVR digital video recorder by gathering video and compressing it into digital information onto a computers hard disk drive. When all works well, this allows a home PC to record up to several surveillance cameras. However, due to reliability concerns and software glitches associated with Windows® as an operating system platform, using PCI cards to record video is not recommended. A home PC is designed to perform many operations at once, but relatively simple functions. Recording digital video requires enormous system resources like computer memory and processor attention. Complete DVR digital video recorders designed specifically to handle recorded video (and solely recorded video) offer the benefits of reliability, as well as simple setup and use, a computer card can never achieve.

Dwell Time The length of time a switcher displays one camera before sequencing to the next.

EIA is the standard monochrome video format used in North America, Japan, and some other places in the world. EIA products are also generally referred to as NTSC because nearly all NTSC products like televisions and VCRs can also handle black and white EIA video. Electronic Industries Association. American standard for B/W camera system.

Effpixels Pixels concerns the operation of a cameras CCD image sensor. A CCD is comprised of hundreds of thousands of tiny pixel elements which translate light to a visible video image. But effpixels pixels must be distinguished from total pixels. Of the total number of pixels contained on a CCD image chip, some are not used for video imaging whatsoever. The number of effpixels pixels indicates exactly how many of the pixels are actively at work to deliver video. A higher number of effpixels pixels tends to indicate a higher tvres camera, though this number may not always describe actual video quality in the important categories of sharpness, color saturation and vividness, as well as low light performance.

Electronic Shutter This feature automatically changes the speed at which light is captured in fields of video by the CCD image sensor. Automatic electronic shutter determines the amount of light available and helps deliver the best quality video by dynamically adjusting for the current lighting conditions by toning down light levels in very bright situations and boosting brightness in low lighting situations. Compensates for moderate light changes in indoor applications without the use of auto iris lenses.

ELC (Electronic Light Control) Compensates for moderate light changes in indoor applications without the use of auto iris lenses. Select this mode when a fixed iris lens or manual iris lens is used.

Electronic Iris (EI) is an electronic implementation of an auto iris. It uses electronics to simulate the effect of opening and closing the iris, by increasing or decreasing the effective shutter time of the camera.

Enclosed Board Camera (a.k.a. module camera) - This term refers to cameras with their electronic board circuitry enclosed or housed inside a protective metal or plastic casing. Enclosed board cameras are not as delicate as exposed board cameras (although all electronics should be handled carefully), but they are also slightly larger and heavier.

Ethernet/Modem indicates a network communication device for computer-type devices. Most DVR video recorders with standard built-in Ethernet LAN connection (with RJ-45 plug) to enable remote internet viewing and/or network operation. Please click here to read more in our DVR frequently asked questions. The most widely installed Local Area Network (LAN) technology. Specified in a standard IEEE802.3.10/100 BASE-T, the most commonly installed Ethernet system, provides transmission speed up to 100 megabits per second.

Exposed Board Camera - This term refers to cameras with electronic board circuitry left exposed on the cameras without a housing or enclosure. These cameras are considered delicate and must be used and handled gently, but are great for some limited applications (like unmanned / radio-controlled vehicles, OEM applications, or body worn video use) because of their slim profile and low weight. In order to provide some degree of protection, all exposed board camera models found on this site come standard with 3M heat shrink coating. For a better protected miniature camera, please consider an enclosed board model.

Evidence Quality Includes specifics such as DVR recordings set at a resolution rate so that faces, number plates etc. can be identified, and accurate time and date information displayed with each recording.

External Sync allows a piece of equipment to take its video synchronisation from another unit, so that it can align itself with the system as a whole.

F-number (f-stop): Optical or lens speed. Smaller f-number means faster lens.

Focal Length indicates the distance between the optical center of a lens and a video cameras image sensor device. For practical purposes, lens focal length refers to a cameras angle of view. Lenses with a higher focal length number have more narrow, telephoto fields of view. A very low number focal length indicates a very wide field of view. It should also be noted that different cameras (photographic cameras, different imager sizes in video cameras, etc.) will deliver different viewing angles with the same focal length lens.

The distance between the centre of a lens, or its secondary principal point and the imaging sensor. Lower lengths give a greater field of view and less magnification. Longer lengths give a narrower field of view and greater magnification. The table below gives an approximate value for the angle of the field of view for lenses of various focal lengths. 30˚ is considered to be a normal view, telephoto (longer) lenses have lower angles. Most CCTV cameras have one of the 3 sizes of imaging devices listed below, 1/4", 1/3" or 1/2". As you can see, this makes a big impact when choosing lenses.

 

Focal Length	Imaging Device Size
	1/4"	1/3"	1/2"
2.8 mm	64˚	80˚	97˚
4.0 mm	45˚	60˚	74˚
6.0 mm	30˚	38˚	57˚
8.0 mm	23˚	30˚	40˚
12.0 mm	15˚	20˚	30˚
16.0 mm	11˚	15˚	22˚
50.0 mm	4˚	5˚	7˚

 

Field - Video is generally "phased" (speed of real time display) at a rate of 2 fields per one frame of video. This type of system is referred to as 2:1 interlace. Therefore, fields per second and frames per second do not mean the same thing (this is common misconception in multiple camera processors and DVR recording). The number of fields per second is always twice as high as the number of frames per second. One video frame is composed of two fields; one field consists of the odd numbered lines in the frame and the other field consists of the even numbered lines.

Field of View refers to the angle at which a camera is able to produce a visible image. This angle can be described in terms of diagonal, horizontal, or vertical degrees. A cameras field of view is determined by its lens configuration. Fixed lenses have set fields of view, while cameras with varifocal or power zoom lenses have adjustable fields of view. The width, height or diameter of a scene to be monitored. Usually determined by the focal length of a lens, the sensor format and the distance to the objects.

Fixed Lens - A fixed focus lens has one set focal length with a specific field of view which cannot be changed. Any camera without a varifocal or power zoom has a fixed focus lens. All cameras offered a Eyespyvideo.com with fixed lenses are focused to infinity. This means that although the user cannot manipulate the field of view, everything in the picture beyond a few inches will be clear and in focus. Objects simply get smaller as they move further away from the camera (unlike a camcorder which may be focused only on a small area with blurred vision of the video image in the foreground or background of that area).

Fiber-Optic Cable One of the video transmission ways, being used for a long distance transmission up to miles.

Flash Memory Or flash RAM (Random Access Memory). A type of constantly powered non-volatile memory that can be erased and reprogrammed in units of memory called blocks.

Flat Panel Antenna - An antenna for wireless with a flat antenna element contained inside a protective weatherproof housing. As a highly directional antenna, a flat panel is intended to send or receive a propugated radio signal on the same axis as the corresponding antenna on the other end (with line-of-sight visibility between the two whenever possible). While omni-directional antennas are great for short range broadcasts because of their versatility, high gain directional antennas are recommended for most long range wireless video applications.

Frame - a full frame of video is the combination of two image fields interlaced together. A frame is one basic screen capture taken by a camera. 30 frames are displayed in one second of realtime video for NTSC format. PAL format is phased at a rate of 25 frames per second for realtime.

Frames per Second (FPS) describes the number of full video frames displayed or recorded within one second. True real time video consists of 30 frames / sec. for NTSC format and 25 frames / sec. for PAL format. Be sure not to confuse frames per second with "fields per second" or "images per second". A complete frame of video is compiled of two separate images (or fields), so the number of fields in one second is always twice the number of frames per second.

FPS Display Rate (a.k.a. screen refresh rate) indicates the number of frames per second a VCR or DVR recorder will display on a monitor for simultaneous viewing. Please DO NOT CONFUSE this specification with FPS Record / Playback Rate. The rate at which each camera is displayed is often NOT the same as the number of frames per second the recorder captures for playback. Many DVR sellers flash "real-time display rate" or "30 frames / sec. display rate" but do not in fact offer realtime playback of recorded video.

FPS Record Rate describes exactly how many frames per second a video recorder can actually capture. Analog recorders like VCRs can easily record in realtime (30 frames / sec. for standard NTSC) or timelapse (fewer than 30 frames / sec. for NTSC). Many digital DVR recorders, however, cannot record actual realtime video. Many sellers try to mislead consumers by advertising FPS Display Rate instead of actual record rate. For most situations, recording rate is the spec to pay attention to. However, please note specifications for digital video equipment are not the only numbers to rely on. In fact, many DVR recorders outperform their specifications upon real world testing while other low quality units often record at a much slower rate than their specs claim.

Frequency is the number of competed cycles of an electronic signal that occur in a given length of time. Frequency is usually measured in cycles per second (Hertz, Hz). For most CCTV industry equipment, frequency is used to describe the RF radio frequency at which wireless equipment operates. Frequency can also be used to describe the cycles of electrical current for the signal system.

FTP File Transfer Protocol a way to exchange files between computers on the Internet.

Gain indicates any increase or decrease in the strength of an electrical signal, often a wireless RF radio frequency signal when considering external antenna equipment. Gain is typically measured in terms of decibels (dB) or a number of times of magnification.

GB Gigabyte.

Genlock    a device that adjusts the frequency of internal sync to an external data.

GHz (gigahertz) is a measure of frequency. 1 GHz = 1000 MHz = 10,000 KHz = 100,000 Hz.

GUI Menu stands for graphical user interface menu. Products which feature GUI menus can be programmed with on-screen guides similar to a home television or VCR.

Gamma a numerical value used to express contrast levels in television pictures. A value of "1" indicates a linear characteristic. Less than "1" indicates a curve or less contrast levels represented by a softer looking picture. The standard for a CCTV camera is ".45" and for CCTV monitors is ".55".

Gamma Correction refers to the correction of linear response of a video camera image sensor in order to compensate for the monitor phosphor screen nonlinear response. Without gamma correction set to the inverse (exact opposite corresponding value) of the monitors gamma, a video camera would not be able to provide a complete video image for a unified display. Gamma correction is measured with the exponential value of the curve describing the non-linearity.

Geometric Distortion the warped look of objects in a television picture due to erratic scanning of the electron beam in the picture tube or vidicon tube. A circle may look egg shaped or a straight line look like a curve.

Ghost refers to a poor image, where the primary signals is weak, allowing a secondary signal to interfere with the picture.

Grade A Chipset - CCD imager chips come in a variety of image and manufacture qualities, but grade A / 1st grade chipsets are always best. These types of CCD chips are made by the finest manufacturers in Japan and are only found in the BEST surveillance cameras. Because of their cost, the newest level of grade A chips are a minority in todays marketplace. Also, older grade A chips do not usually compare to the newest revisions and models. We carry cameras built with only the highest quality, and latest grade A CCD imager chips to bring our clients the absolute best image quality at an affordable price.

Grey Scale a pattern of vertical bars with shades of grey starting with white and gradually getting darker grey until ending at black. The pattern is used to test the ability of a CCTV camera to reproduce true white, black and the varying steps of grey in-between.

Hard Disk Drive (HDD) is a magnetic media storage device for recording digital information (like that used by computers or digital DVR video recorders).

HDD Capacity indicates the amount of information which can be stored on hard disk drive. This figure is measured in bytes. 1 GB = 1016 MB = 1032256 KB = 1048772000 bytes.

HDD Speed indicates the speed at which a hard disk drive is capable of encoding information. While many DVR sellers only use inexpensive, slow generic HDD drives (typically 5400 RPM with no buffer in place), DVR recorders are only equipped with 7200 RPM hard disk drives with 8 MB buffers from trusted brand names like Seagate, Western Digital, and Maxtor.

Homing a term used to describe a type of automatic sequential switcher, which will stop sequencing and remain on a single CCTV camera input displayed on the monitor when a switch or button is depressed. This switcher has only one monitor output.

Housing Protective enclosure that a camera can be placed in to protect it from outside weather conditions.

Hue Corresponds to colors such as red, blue, etc.

Hz (hertz) is a measure of frequency (indicates cycles per second in an electronic or RF signal). 1 GHz = 1000 MHz = 10,000 KHz = 100,000 Hz.

H.264 is a standard for video compression. It is also known as MPEG-4 Part 10, or AVC (for Advanced Video Coding). It was written by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) as the product of a partnership effort known as the Joint Video Team (JVT). The ITU-T H.264 standard and the ISO/IEC MPEG-4 Part 10 standard (formally, ISO/IEC 14496-10) are jointly maintained so that they have identical technical content.

H.264
The latest video compression standard, H.264, is expected to become the video standard of choice in the coming years. It has already been successfully introduced in electronic gadgets such as mobile phones and digital video players. For the video surveillance industry, H.264 offers new possibilities to reduce storage costs and to increase the overall efficiency. H.264 (sometimes referred to as MPEG-4 Part 10/AVC) is an open, licensed standard that supports the most efficient video compression techniques available today. Without compromising image quality, an H.264 encoder can reduce the size of a digital video file by more than 80% compared with the Motion JPEG format and as much as 50% more than with the traditional MPEG-4 Part 2 standard. It is the magnitude of these numbers that makes H.264 highly relevant for video surveillance applications. 

 
Bit rate comparison for a 115 seconds video stream, given the same level of image quality, among different video standards. The H.264 encoder was at least three times more efficient than an MPEG-4 encoder with no motion compensation and at least six times more efficient than Motion JPEG.
Reduced storage and bandwidth costs
One immediate benefit of the drastically reduced file sizes is the impact on storage and bandwidth requirements. For the same amount of video data, with the same image quality, a video surveillance system supporting H.264 compression will basically reduce the storage cost and bandwidth occupancy by at least 50% compared to when using conventional compression technologies. As the systems grow larger, and the requirements for high resolution images in combination with high frame rates increase, H.264 will be a key differentiator between various system solutions.
Higher resolution and frame rate
Depending on application needs, there are various ways to benefit from the impressive compression rate of H.264. Today, it is common to choose a limited frame rate or lower resolution in order to stay within the specified storage limitations of an application. This has a negative impact on the video images, which become either blurry or less detailed. Introducing video surveillance equipment that support H.264 compression in such an application will enable several combinations of increased frame rate and image resolution, thus providing higher image quality.
Accelerating use of megapixel cameras
H.264 is expected to accelerate the adoption of megapixel cameras within the surveillance industry. One of the current trade-offs of megapixel cameras is the large size of the recorded video data. As mentioned above, H.264 reduces the large file sizes without compromising image quality. It is likely that the highly efficient compression technology find the quickest traction in applications where there are demands for both high resolution and high frame rates, such as in the surveillance of airports, retail stores, banks and casinos.
Looking ahead
H.264 presents a huge step forward in video compression technology. With support from many industries and applications for consumer and professional needs – e.g. QuickTime, Flash, YouTube, iPod and Play- Station 3 – H.264 is expected to replace other compression standards and methods in use today. As the format becomes more broadly available in video surveillance equipment, system designers and integrators will need to make sure that the products and vendors they choose support this new open standard.