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FAQ List on CCTV Products
Auto Iris
In Most surveillance application ,it is not realistic for an operator to manually adjust the lens iris since multiple cameras are used. Auto Iris is a convenient function that detects the amount of light entering the lens and automatically opens/close the iris to maintain appropriate exposure. Auto iris lenses are especially suited for use on outdoor surveillance cameras installed in parking lots, shopping centers,or train stations where light conditions can change over time.
IR / Infrared Cut Filter
The IR cut filter is an optical filter placed between the lens and the images and is used in all color cameras. To understand the function of this filter,a review on the characteristics of human eye in comparison to a camera imagine is required.During the nighttime when visible light is not available, cameras can take advantage of this IR light to capture images buy removing the IR Cut Filter,the camera imager captures the ambient IR light or light emitted from Ir illuminators such as LEDs. In this mechanism,the camera imager simply detects the IR light as energy instead of color lights. Therefore,images are provided only in black and white.
IR Lens- In recent 24 Hours surveillance application,cameras with a day/night function have become extremely popular. Designed for such application,IR lenses offer the ability to handle both visible light and IR light.
Day and Night Function
Camera are required to capture clear images both during the day and night.During the day when visible light is available, the camera uses this light to capture color images,in asimilar way to the human eyes. Coversely,during the night when visible light is insufficient,the camera uses the near IR light,which typically exists in any enviroment even during the dark. This night mode is selected by removing the IR cut filter,which blocks unnecessary IR light during day uses.
Optical Zoom/ Digital Zoom
In today’s video camera, the word ZOOM refers to two type of zoom functions- OPTICAL zoom which is performed within the camera lens, and Digital zoom which is performed electrically within the camera unit. Optical Zoom changes the area of image that is directed to the image,and therefore does not introduced picture quality degradation. Conversely, digital zoom electrically crops a part of the image and magnifies it . Since missing pixels must be created to enlarge the image,the picture quality drops in proportion to the zoom vuale.
Privacy Mask
Privacy Zone Masking is a feature used to protect personal privacy by concealing private areas in the camera's field of view.For Example, house windows,doorways and car number plates that are not subject to surveillance. This ensures that the same object for which privacy must be kept is always hidden,regardless of the ptz position.
A Video Balun enables the transmission of video using unshielded twisted pair wire instead of coaxial cable. The word "balun" comes from combining the terms balanced and unbalanced. The function of a balun is to transform an unbalanced signal into a balanced signal. When video signal is transmitted through coaxial cable, the distance traveled by the signal is limited because the signal is in the form of an unbalanced signal that is susceptible to Radio Frequency Interference or noise. Coax cable incorporates special shielding to minimize noise. Video Baluns transform the video signal into a balanced form in which each wire in the twisted pair transmits an identical signal with opposite polarized magnetic fields. Noise affects each signal equally. When the signals are combined, the noise is cancelled out. By using a designed balun, an unshielded twisted pair wire can transmit video for much longer distances than coax cable and with a lower cable cost.
BNC Connector
BNC is a connector for coaxial cable that is most commonly used for CCTV installations.
CCD Charge Coupled Device
Charge Coupled Device, CCD, is one of the two main types of image sensors used in security cameras. When a video is recorded, the CCD is struck by light coming through the camera's lens. Each of the thousands or millions of tiny pixels that make up the CCD converts this light into electrons. The number of electrons, usually described as the pixel's accumulated charge, is measured, and then converted to a digital value. This last step occurs outside the CCD, in a camera component called an analog-to-digital converter.
C Mount Lens & CS Mount Lens
There are two main types of lenses used in security cameras. 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 today's 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 security cameras are CS.
CO-Axial Cable
A type of cable typically used in cctv installations that has a central conductor, surrounded by a shield sharing the same axis. The shield can be made from a variety of materials including, braided copper, or lapped foil. There are various standards for specific types of co-axial cable. The cable used for normal CCTV installations is called RG59.
Composite Video
The encoded output of a surveillance camera whereby the red, green, and blue video signals are combined with the synchronizing, blanking, and color burst signals and are transmitted simultaneously down one cable.
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).
DVR (Digital Video Recorder)
A Digital Video Recorder is a generic term for a device that is similar to a VCR but records television data in digital on a hard drive as opposed to a VCR tape. A DVR looks like a VCR and has all of the same functionality of VCR (recording, playback, fast forwarding, rewinding, and pausing) plus the ability to skip to any part of the program without having to rewind or fast forward the data stream.
Dwell Time Programming
The length of time a switcher or CCTV multiplexer displays one camera before sequencing to the next. Multiplexers with dwell time programming capability allow you control this length of time.
Focal Length
The distance between the center 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 and also considering the size of the imaging device (CCD). Most CCTV cameras have one of the 3 sizes of imaging devices listed below, 1/4", 1/3" or 1/2". Almost all of CCTV Camera Pros cameras have 1/3" Sony CCD imaging devices.
Gamma Correction
Gamma correction controls and adjusts the overall brightness of an image for consistency.
A quality brand of DVR Cards made for Windows based computers. A complete line of Geovision DVR Cards can be seen here:
Geovision DVR Cards.
The total opposition offered by a device to the flow of an alternating current. Measured in Ohms.
Internal Sync
Devices with internal sync have an internal crystal to provide sync pulses without needing reference from any external device.
IP Waterproof Rating
IP waterproof ratings are a BSi standard measurement for how waterproof something is. Many security cameras or camera housings are designed for outdoor use need to be waterproof. The IP rating number has two digits, and optional letters after them. E.G IP66 and IP68. The first number defines the protection against ingress of foreign objects. 0 is the lowest rating and means non-protected. 6 is the highest rating and means dust tight and protects against access with a wire. The second number defines the level of protection against ingress of water. 0 is the lowest rating means non-protected. 8 is the higest rating and means protects against continuous immersion in water.

For further information, see the BSi website at
www.bsi-global.com or www.bsi.org.uk
JPEG is a standard for the encoding and compression of images. JPEG is used in the video surveillance systems to compress and store individual frames of video. JPEG was developed by the
Joint Photographic Experts Group.
LCD (Liquid Crystal Display)
Technology used for flat screen displays.
Connecting an additional device in parallel with an existing video cable. For example, when driving a video recorder as well as a monitor from the same video signal.
Unit of light illuminance used as a measure of low-light recording capacity in security cameras. Cameras with a Lux rating of 0.2 Lux or less would be considered low-light cameras. It is not possible to get good color definition in low light levels, so in general low light cameras are always black and white. Day/night cameras use electronics to switch from color during the daytime, to black/white during night or low light conditions. Many low light cameras also use infrared, which is useful in zero light conditions. The lower the LUX rating of a camera, the better it will see in low light.
This refers to the part of a video signal that carries the monochrome information. i.e. brightness information.
Motion Picture Experts Group (MPEG) released MPEG-4 encoding in 1998. The basic idea behind MPEG is that compressed images are compared before being transmitted over the network. The first compressed image is used as a reference and compared to the images that follow it in the video sequence. The first image is transmitted over the network along with the parts of the following images that differ from the initial reference image. The viewing application on the receiving end of the transmission then reconstructs all images based on this information and displays the result. This is a simplified description of how MPEG-4 works.
This is a device that takes inputs from 2 or more video channels and combines them into one signal. This is often done by using time division multiplexing, which interleaves frames from each channel in such a way that they can be split out again. Frequency division multiplexing uses different frequencies to achieve the separation of the signals.
Network Camera
This refers to a camera that is designed to record pictures and transmit them directly over a computer network or internet connection. Network cameras normally do not have any analogue video outputs. The images are encoded directly in one of the standard compression techniques, such as JPEG or MPEG.
NTSC is an abbreviation for the National Television Standards Committee. The term "NTSC video" refers to the video standard defined by the committee, which has a specifically limited color gamut, is interlaced, and is approximately 720 x 480 pixels, and 30 frames per second (fps). This standard is used in North America.
OSD (On Screen Display)
A method of displaying set-up information and/or instructions on a display monitor.
PAL is an abbreviation for Phase Alternating Line. This is the television display standard that is used mainly in Europe, China, Malaysia, Australia, New Zealand, the Middle East, parts of Africa, and other parts of the world. PAL uses 625 lines per frame and a frame rate of 25 frames per second.
Pinhole Lens
This is a type of lens with a very small aperture. Normally used for covert applications, where it can easily hide behind or within another object.
A device that forwards data packets along networks. Typically when referred to in CCTV installations, a router is used to connect a surveillance DVR and a computer to a single internet connection. A router can also be used to connect multiple IP based security cameras to a single internet connection.
A pixel refers to an individual area on the surface of the imaging device, normally a CCD. It is made from photosensitive material which converts light into electrical energy. In the context of a display monitor, a pixel is also referred to as an individual area on the surface of the screen which converts electrical energy to visible light.
RS-232 is a communications standard for serial communications between devices. In CCTV, this can be communication between a contoller and a surveillance camera. The RS-232 standard allows for the connection of two devices through a serial link, and is the protocal used for serial connections in computers. RS-485 allows for serial connections between more than 2 devices on a networked system and is defined below.
RS485, also referred to as EIA-485 is a communications standard for serial communication between devices. When talking about surveillance systems, RS-485 is typically used as the protocal to allow computers and remote controllers to control the activity of cameras such as pan, tilt, rotate, and zoom operations. RS485 is an updated version of the original serial protocol, RS-232.
Signal to Noise Ratio (S/N Ratio)
This is the ratio between the signal strength and the noise levels on an audio or video signal.
Television Lines (TVL)
This is a measure of the resolution of a video device. The higher the number, the higher the resolution is. 380 TVL is considered medium resolution. 480 TVL or greater is considered high resolution.
Varifocal (Zoom)
This refers to a type of lens that has the capability to change the focal length. This allows adjustment of the magnification and field of view of the security camera.
WDR Security Cameras
A WDR security camera (Wide Dynamic Range) is used for capturing clear images of objects surrounded by a strong back light, while still keeping the background visible.
What is ONVIF?
Onvif BBS LOGO for this .In May 2008, Axis by the joint Bosch and SONY announced three parties will work together to form a Open Network video product standard international Network Interface development BBS, named ONVIF (Open Network Vidoe Interface Forum), And with the principle of openness, open to establish open standard of the industry.
ONVIF standard for network video equipment to exchange information between the general agreement definition, including real-time video search and the device, audio, yuan data and control information, etc. Network video products which can provide a variety of possibility, that end users, integrators, consultants and manufacturers can easily benefit from it, and get high price, more flexible solutions of market expansion, the opportunity and lower risk.
According to information, there is a part of the enterprise and telecommunications operator has made the related industry standard, there are also some enterprise alliance put forward some of the interconnected enterprise standard. ONVIF is facing the global, the starting point is to make a completely open standards. The standard's main goal is to promote different network video equipment brand the integration, help manufacturers, software developer, and independent software vendors to ensure that the products are interconnected interoperability, very suitable for an enterprise market.
From ONVIF website can understand, from the end of last year has formally opened to recruit members. At the same time to adapt to the different level of participation, ONVIF also provide different grades of membership, can choose senior and intermediate or user membership level. BBS now accept nearly 40 members of the house. Among them, the senior members have 12 home, in addition to three launched the company, panasonic, samsung, cisco, Siemens, TI, and other famous brand among them, and domestic kangwei depending on the sea and zhejiang dahua is also a senior member of ONVIF BBS.
Implement standard of the process is also an important means of purify market, help to integrate security market resources, and reduce a lot of repetitions of the development of labor, and meaningless human, material and time consumption, improve the reliability of the product. Greater interchange and compatibility of collective upgrade to industry, eventually give consumers greater benefits. Believe in the open standard platform will be unified greatly promote the healthy development of the security monitoring industry.
ONVIF are dedicated to global open interface standards to the promotion of Internet video in the application of the security market, the interface standards will ensure that different manufacturer production network video product has interoperability. In November 2008, BBS officially released the first edition ONVIF codes--ONVIF core standard 1.0. As video monitoring network application, the industrial chain of division of labor will more and more fine. Some manufacturer specialized in cameras, some manufacturer specialized in DVS, some manufacturers may be specially do platform, and so on, and then through the integration of integration, to provide the final customer. The industry cooperation pattern, have an urgent need industry provide more and more standardized interfaces platform.
How to pass the domain name to access the camera?
The camera can be accessible via the domain name, domain name to bind to a router or a camera to use the domain name, if no domain requires the application domain.
A binding Router: General router supports domain access router, find domain name page, enter the domain name and password, the router has and domain binding.
B Camera binding in camera IE interface parameter settings - dynamic domain name domain name and password input and select open.
The binding domain is needed after the port forwarding: camera default HTTP port is 80, RTSP port 554, RCFG port 8001.
If the port is occupied, need to change. In IE interface parameter settings - network settings change can be. The gateway must fill in the forwarding port router IP address. In the router's forwarding settings for port forwarding, set after the success, will be in the network through the domain name + camera HTTP port to access the camera.
The camera IR-CUT switching abnormal?
Because the camera mounted on the IR-CUT board, camera power IR-CUT will self-test switch reset.
A infrared light, IR-CUT does not cut in black and white. Login IE browsing interface, within the parameters set up the - CMOS parameter in the infrared switch selection for ON, you can click ok.
B The camera is energized, picture display black and white, not cut in color. Login IE browsing interface, within the parameters set up the - CMOS parameter to switch level change can.
C The camera is energized, screen was red, switching. Unplug the power to restart the camera or camera lamp cover plate photosensitive resistance, let IR-CUT switched several times, so that the screen normal.
How to change Camera IP Address?
Modified camera IP address generally has 2 methods:
A The connection camera, log in to the IE browser, within the parameters set up local settings change camera IP.
B The connection camera, open the search tool, click Search, to find the camera IP address after stopping, and then selected camera IP, click Update Ip, insert new camera IP you can click ok.
Due to our camera firmware update to 1806H, so less than 1806H version to upgrade.
First connect the camera, IE login in the system settings, click to upgrade the system tool; click on the first Upload, select the home upgrade file, click on the second Upload, select the rootfs upgrade file, the file upload completed click system upgrades; and then wait for the page to prompt the upgrade is complete, complete need to close to open the IE browser. ( the upgrade process do not power off, or else it could lead to a crash and network board )
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