Aberration is any inherent deficiency of a lens or optical system. Aberrations are responsible for imperfections in shape or sharpness of the image.

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.

AGC is Automatic Gain Control, an electronic circuit that amplifies the video signal when the strength of the signal falls below a given value.

ALC is Photometric control, measures light intensity. Determines the iris reaction sensitivity. Sensitivity is increased when the potentiometer is turned towards PEAK, and decreased when turned towards AVERAGE.

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 electical 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.

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 adaquate power for video cameras and other devices so long as the +/- polarity is correct and the battery's output voltage falls within the device's safe operating range.

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

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.

Analog indicates a particular electical signal which conveys electronic data (i.e. a video signal or audio signal). Information carried over an analog signal is a representation of data by continuously varying quantities. An analog electrical signal has a different value of volts or amperes for electrical representation of the original excitement (light, sound, etc.) within a dynamic range specific to the analog device.

Angle of view may be expressed in Diagonal, Horizontal, or Vertical. Smaller focal lengths give a wider angle of view.

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 of a lens on a video camera controls the amount of light which is allowed to reach the image sensor. Aperture is listed in terms of an F-stop number. As F-stop number increases (i.e. F/1.4, F/1.8, F/2.8), the amount of light permitted to reach the image sensor decreases.
Aspherical Lens is lens one or more of whose elements has a non-spherical surface. Aspherical surfaces are shaped to reduce the spherical and other aberrations.

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.

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 transmitter's ability to broadcast sound, or a video recorder's ability to record audio.

Audio Input Plug refers to the type of connector plug for a device's 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 found on Eyespyvideo.com require line-level microphone connections. For compatibility's sake, all microphones found on this site are line-level and contain preamplifiers.

Audio Output Plug refers to the type of connector plug for a device's 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.

Automatic Gain Control (AGC) is a built-in feature of every camera found on Eyespyvideo.com. This term refers to a circuit within the camera which regulates image brightness levels for optimum performance and highest video quality.

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