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COP:
Helpline: 0870 7442298
GEOVISION:
Helpline: 01462 708825
TELEEYE:
Helpline: 0118 95337
PRODUCT INFORMATION
To be read in conjunction with CCTV Quotations from
www.classic-security.com
www.camcomsolutions.com
www.webvision.tv
NB: This guide has been produced by Caspar Cook and can be used in conjunction with any CCTV quotation and is to aide the procurement of CCTV services by giving a step by step simple observations and recommendations based on the technical ability of individual products.
INDEX
General CCTV Description Domestic
General CCTV Description Commercial
Analogue Cameras
Digital Cameras
Web Cameras
Networked CCTV Systems (Video across LAN)
Digital Recorders
Time Lapse Video Recorders
Full Function Cameras (Pan, Tilt, Zoom, (PTZ))
Lenses (Vari Focal, Zoom, Focal Length)
Installation Standards (EN50132, 2001)
Data Protection Act
Log Books, Video Archiving
1. GENERAL CCTV DESCRIPTION DOMESTIC
System Types and Budgets
Budget, DIY stores and the Internet, you pay for what you get, so read the specifications carefully.
Name brand observation systems and DIY kits come with good bloodlines - a good half way house.
Professional component built systems allow cameras and hardware to be purchased for exact requirements such as seeing in the dark, infrared, focal length etc.
Recording
Recording in the DIY market is normally via a time lapse VCR that allows the client to record 24 hrs of video onto one standard VHS tape. For shorter periods you can use a domestic VCR in long play mode, which will record up to eight hours.
Digital reordering is the latest technology, however consideration should be given to budget systems with free software, video motion detection, and hard disk capacity. It requires your PC to be on for the duration of the recording and there is a delay in video motion detection. Only professional systems can match or better a time lapse VCR and the hardware can run into thousands of pounds. Uncompressed video can fill a 20Gb hard drive in less than 10 minutes. One advantage is that professional systems can be controlled and monitored across the net via ADSL and broadband, if installed. This is useful for nanny cams and builder cams.
Legally
Legally - if you want to use as evidence in a Court of Law
· Sites should display CCTV signs to warn third parties of video surveillance
· Registration of the system with the Data Protection Agency. There are minimum requirements
· Record where possible only your property. General recording is acceptable
· Keep a logbook of events that include details of who inserted the tape and on what date the VCR tape was used
· Keep a library of tapes for either 7 or 31 days and label either as days or dates
· Professional companies normally provide the above advice and log books (see advice)
Colour or black and white
Colour is good for shops and well lit areas, however, night surveillance should be black and white since the cameras are up to four time more sensitive or use more expensive colour-mono cameras which switch from colour to black and white at night. Use your security lights to enhance the night time surveillance
Deter or Catch a Thief
The general view is that if you want to stop crime the cameras should be easily viewed and high profile, within the grounds of reason, in order to highlight the deterrent factor. Hidden cameras, known as covert, will catch a thief. The legal ramifications should be covered and understood. The bottom line is that it's better to have some evidence than nothing is at all.
Advice
Take advice from your Local Crime Police Prevention Officer (CPO) or Security governing body such as the www.SSAIB.org or Internet sites such as www.webvision.tv.
To identify a criminal in court using CCTV will require the legal aspects covered as shot.
2 GENERAL CCTV DESCRIPTION COMMERCIAL
System Types and Budgets
The commercial market is vast and can be divided into two areas, small commercial with 4-6 Cameras and commercial being more than 6 Cameras.
Systems can comprise of static or full function cameras with pan, tilt and zoom (PTZ) and can be colour, mono (black/white) or specialised cameras which can switch between the two.
Generally, low light surveillance utilises mono cameras or colour mono cameras and well lit areas can benefit from full colour observation.
Systems that are not monitored by personnel require a number of static cameras whereas security controlled systems can benefit from less cameras, but less cameras utilising PTZ.
Camera types can be analogue or digital (see items 3 and 4).
Recording
The archiving of video can be carried out by time lapse VCRs (item 8) or digital recorders (item 7). Care should be taken in the procurement of digital systems as the capital outlay can be inappropriately assigned to a product that is not worthy of its cost. A full demonstration is always recommended from the manufacturer or installing company.
Legally
· Site should display CCTV signs to warn third parties of video surveillance
· The System should be registered with the Data protection Agency. There are minimum requirements
· Record where possible only your property. General recording is acceptable
· Keep a logbook of events that include details of who inserted the tape and on what date the VCR tape was used (see item 13)
· Keep a library of tapes for either 7 or 31 days and label either as days or dates
· Professional companies normally provide the above advice and log books (see advice)
Colour or Black and White
Colour is good for shops and well lit areas, however, night surveillance should be black and white since the cameras are up to four time more sensitive or use more expensive colour-mono cameras which switch from colour to black and white at night. Use your security lights to enhance the night time surveillance
Deter or Catch a Thief
The general view is that if you want to stop crime the cameras should be easily viewed and high profile, within the grounds of reason, in order to highlight the deterrent factor. Hidden cameras, known as covert, will catch a thief. The legal ramifications should be covered and understood. The bottom line is that it's better to have some evidence than nothing is at all.
Advice
Take advice from your Local Crime Police Prevention Officer (CPO) or Security governing body such as the www.SSAIB.org or Internet sites such as www.webvision.tv.
3 ANALOGUE CAMERAS
Analogue cameras are available in colour, mono (black/white) and colour mono (day/night cameras). The voltage of the camera can be mains or ultra low voltage such as 12volts dc. Where cameras are accessible to the general public or in areas such as petrol stations, the low voltage option is recommended.
The quality of the camera is measured in lines of resolution whereby 300 is low and 580 is high. This is also linked to the image device called a CCD chip (Charged Coupled Device), which are available in various sizes, one quarter, one third, half and inch formats whereby a 1" CCD device is of broadcast quality. The average CCTV system utilise 1/3rd " CCD chips and is deemed medium definition.
Analogue cameras can also be branded as digitally enhanced which is not a digital camera. The image produced by the camera is digitally enhanced prior to analogue transmission. It can be said that all analogue cameras are digitally enhanced since the initial pickup device is digital. However, the wording can mislead a technical specification.
4 DIGITAL CAMERAS
Digital cameras are the latest technology and can be connected directly to existing PC networks (LAN) with the ability to be recorded directly via third party software. The digital camera range is limited and specification is normally limited to an individual camera that is required to be used for projects that involve digital distribution such as "web cams".
It should be noted that where the network is not dedicated to video, adding cameras can severely decrease the bandwidth available on the network and can cause disruptions to data transfers, Internet and e-mail. Where large numbers of digital cameras are required, it is recommended that the network is dedicated only to the surveillance system.
The majority of budget network cameras cost is in the network transmission, so the quality of image suffers. This is also proportional to the bandwidth ie; a higher quality image will use more network bandwidth.
It is recommended in most cases that conventional analogue cameras are utilised for specialist work and then converted via digital recorders into the digital format. The analogue market is vast and the options of specification endless, they are also more cost effective.
5 WEB CAMERAS
The technical description of a web camera can be seen in item 4. The terminology of the phrase "webcam" is often misunderstood in that any camera connected digitally to the Internet can be described as a webcam. This includes cheap PC cameras supplied free with home PC's.
A webcam should not be confused with remote site surveillance whereby a multi site CCTV system is monitored over the Internet or private network. Webcams are normally one or two cameras used to monitor projects such as building sites, builders, nannies, second homes or remote entrances etc.
Specialist software can be used to view the cameras, but a true webcam should be able to be viewed within an Internet browser such as Microsoft's Internet Explorer. This allows the images to be viewed from anywhere in the world at any time without the need for additional software.
6 NETWORK CCTV SYSTEMS
Network CCTV systems is where digital cameras or converted analogue camera images are distributed across a PC network.
Care should be given to the amount of cameras on a network if it is to be shared with existing PCs and it is recommended that a dedicated network is utilised if more than two or three cameras are to be installed.
Network camera systems are particularly useful where cabling is limited, or to be limited, since it is possible to send a number of images simultaneously down one data cable such as CAT 5, however, by still observing the bandwidth issues. Distance is limited to the rules of CAT 5, which is currently 90 metres whereas analogue systems can be run in excess of 500 metres.
7 DIGITAL RECORDERS
Digital recorders replace time lapse video recorders and the requirement of video multiplexers. The digital unit digitises analogue CCTV signals and records them to hard disk. The evidence can then be archived in part using floppy disks and Cdrs.
The specifications however of digital recorders should be closely monitored, since any digital recorder can be seen to meet a required specification. This is explained in the following paragraph which compares a digital recorder to a VCR. Client's wishing to upgrade their systems from analogue to digital recording should understand at a minimum, the following information.
Analogue video (PAL in the UK) viewed in real time is made up of 25 single images per second which is known as "frames per second" (FPS). The image size is not important since it can be played back on a TV monitor of different sizes without loss of quality. The quality of the video image is directly proportional to the quality of the camera. This is to say that one camera connected to one VCR will be recorded at 25 frames per second and when played back, will provide a near perfect smooth image which can be compared to home videoing.
Once more than one camera is recorded using a video multiplexer, the simple calculation of the amount of cameras divided by the FPS will provide the record rate per camera ie; sixteen cameras recorded by a video recorder at 25 FPS (3 hour mode) will provide one image per camera every 1.56 seconds. Once the time lapse video recorders record rate is increased ie; to 24 hours, the FPS capacity is then reduced and thus, the record rate per camera is further increased, so careful attention to the amount of cameras and the FPS which affects the overall amount of information recorded.
The images are recorded onto a standard VHS tape or SVHS tape, dependent upon system parameters and a library of tapes is kept for 7 or 28 days. This library of tapes effectively allows a whole day's worth of information to be archived/stored and a simple replacement tape can be inserted to keep the library intact.
Digital recorders have no technical resemblance to a VCR. The video image is digitised and recorded as a "JPEG" computer file as well as a number of other formats. The computer file size is proportional to the image size and definition. A digital images size and definition is important since the image cannot be expanded without loss of definition unlike an analogue image.
Digital recorders can be set to record at different video compression rates which is directly proportional to the definition ie; higher compression equals lower definition. This is normally provided from selections such as low, medium and high whereby medium is deemed to be similar in definition to that of a time lapse VCR.
Therefore, to enable a comparison, a digital recorder should be set up to a level of recording that is equal to a time lapse VCR in order to warrant the capital outlay. This is the Achilles Heel of a digital recorder since recorded images in high quality at the rate of 1 image per camera every 1.56 seconds uses massive amounts of storage measured in Gbs. Using 16 cameras as an example, means that a comparative memory capacity of 320Gbs will give a record time of approximately 12 days, thus, if you wish to record 28 days in a commercial environment, either less information FPS have to be recorded per camera or lower quality images are recorded. IT IS ALSO TRUE TO SAY THAT A 40GB HARD DRIVE COULD RECORD 28 DAYS, BUT WITH LITTLE DEFINITION AND A VERY POOR FPS.
The second drawback is that although the information is archived to the disk due to it's capacity, it is impossible to keep a secondary copy, as an example, 320gbs is equal to 222,222.00 floppy disks. Therefore, only incidents can be archived normally to Cdr, which has a capacity of 750 megabytes which is approximately 5 minutes worth of images from 16 cameras.
The conversion from analogue to digital has many plus points, but the pitfalls should be noted, especially by an over zealous sales representative and generally, the client should opt for the highest possible hard drive capacity he can afford.
The plus points are that most professional digital recorders can record up to 50 FPS which is double that of a analogue VCR, thus our equation of cameras verses FPS allows us to capture more information. The information captured can never deteriorate since it is recorded digitally which are the two main selling points of a digital recorder. The digital recorder also allows immediate access to files without the necessity to stop recording. The hard disk recorders can also be networked to allow remote access and more than one user to observe and control recorded images.
8 TIME LAPSE VIDEO RECORDERS
The description and use of time lapse video recorders is covered in the comparisons between analogue and digital recorders in item 7 above.
9 FULL FUNCTION CAMERAS
Full function cameras are where the camera can be positioned and controlled by moving left, right, up and down commonly referred to as "PTZ". For the choice of cameras, see items 3 and 4 above.
Most PTZs are now dome type and are available as slow and high speed units and are proportional in cost. The control can be via a joystick or PC control, however, if connected to a network, there can be issues relating to network LAG, whereby the delay between transmission of the image and control of the camera can sometimes cause visual conflict.
10 LENSES
Lenses for cameras can be described as vari focal, zoom or focal length. Focal length is measured in millimetres (mm) whereby 4mms is wide angle and can capture large amounts of information. 6mms can be compared to the human eye without peripheral vision. In essence, the higher the focal length, the closer the image appears ie; a 100mm focal length lens would appear to bring images very close.
Zoom lenses are measured in a ratio such as 6:1, which is the highest focal length divided by the smallest focal length to give a ratio.
Vari focal is where a lens has a manual ability to adapt between a focal range ie; a 4-8mm vari focal, this allows fine tuning of the video images or subsequent alterations without the requirement of changing lens.
11 INSTALLATION STANDARDS
The installation standard for CCTV is EN50132: 2001. Systems should be installed to these standards and installing companies registered with governing bodies and inspectorates such as the "SSAIB" (Security Systems and Alarms Inspection Board) will have their systems audited to these standards. Copies of these standards are available from the " BSI" (British Standards Institute).
12 DATA PROTECTION ACT
Please be aware that the 1998 Data protection act is now in force. If the end user has a CCTV system installed after October 1998 they must register the system with the Data protection registrar.
Many parts of a CCTV system are now governed by law, which includes assessment, siting of cameras, quality of images, processing of images, data access and third party rights. Our quotation will meet the relevant technical standards.
The minimum technical requirements after registration are for the logging
Should this quotation contain a digital recording system. The recording capacity of the hard disk as with all digital recorders, can only be estimated, therefore the amount of archive media is approximate and may need to be reviewed in experience of the actual installation. This is because the amount of memory used for each picture is dependent on some of all of the following: Number of cameras, the mixture of colour/mono cameras, picture content and picture movement.
13 LOGBOOKS VIDEO ARCHIVING
The requirement of the Data Protection Act requires the user to log the various aspects of recorded video images whereby who is responsible for the system and instigated the recording aspect or archive aspect of the procedures. Various different forms of logbooks are available from a simple word text to printed CCTV logbook folders. In general, information has to be kept in order to allow the information to be used as evidence in a court of law. Failure in this area would deem the evidence as non-admissible, an example of a printed log can be seen below
CLASSIC SECURITY SERVICES
0208 7660150
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