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The Sony Guide to
CCTV
Issue
3
this is not a rehearsal.
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Contents 1 Introduction 2 Case Studies 6 What is Closed Circuit Television? 7 When and Where should it be used? 8 Light 11 Choosing a Camera 15 Selecting the Correct Lens 18 Which Monitor? 20 Transmission of Video Signals 23 Video Switching and Multiplexing 25 CCTV Systems Control 26 Recording 28 Sony CCTV Products 32 Basic CCTV Terminology
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Introduction In recent years... there has been no shortage of innovations in the CCTV industry with manufacturers competing to better meet the needs of crime prevention. Most visibly, more surveillance cameras have appeared in more public areas than ever before, proving their effectiveness and generating interest in maximising the benefits of operating a surveillance system. The bewildering choice of different equipment and the desire for practical knowledge in this area demonstrates that, as wi
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case study Sony gives Newham a clearer picture Newham District Council has the largest local authority CCTV control room in the country, monitoring over 200 cameras in the heart of London’s East End. Recently, it has installed additional Sony Trinitron colour video monitors, bringing the total in the system to 73 screens. As well as fighting crime, the system is used for traffic surveillance, including monitoring a new bus lane system, controlling vandalism, general council activity and ensurin
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case study Underground Security Expanded The latest phase in London Underground’s multi-million pound refurbishment programme includes the installation of 60 Sony CCTV cameras at three of South London's busiest central stations: Brixton, Pimlico and Vauxhall. Part of an integrated passenger security system, pictures from the cameras at all three stations can be selected and received at a specially built control room at the Brixton station where Sony S-VHS time-lapse VCRs are located, providing
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case study Daewoo savings with Sony PMS In the face of rising manned guarding costs, Daewoo Cars has installed a new remote surveillance alternative – a monitoring codec from Sony. Daewoo was spending over £1 million a year on manned guarding services for its 25 forecourt and showroom sites until a remote video monitoring service introduced a complete design, commissioning and monitoring package based around remote CCTV surveillance. Daewoo's brief was to protect vehicles and premises while al
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case study Farsight Chooses the HSR-1P One of the UK’s largest remote video monitoring companies has chosen the Sony HSR-1P to replace its existing complement of time-lapse video recorders and multiplexers. On a weekly basis Farsight (UK) Ltd, based in Peterborough, makes and receives in excess of 20,000 video patrols/alarms from its diverse mix of clients situated throughout the UK. Farsight is currently using two HSR-1P digital surveillance recorders and 40 DV270 tapes to meet all its recordi
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What is Closed Circuit Television? Closed Circuit Television (CCTV) is a television system which operates on a ‘closed loop’ basis. Unlike broadcast television, which is available to anyone with a suitable receiver, CCTV pictures are only available to those directly connected to the loop. Colour Video Monitor Video Out (Coaxial cable) DC12 V DC12 V AC outlet power supply CCTV was first used in the 1950s and has since become an essential element in any professional security system. In most insta
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When and where should it be used? Security and surveillance are the most accepted applications for CCTV systems. With the use of CCTV, managers and supervisors can control risks and minimise costs efficiently and with the minimum of disruption. Security applications As well as acting as an effective deterrent, CCTV helps managers to monitor: n Access to secure areas n Unauthorised activities n Theft or criminal damage n Personal safety Surveillance applications CCTV has many applications in
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Light The human eye and the camera lens operate on completely different lines. Although the human eye adjusts automatically to various light conditions, the camera is inherently less flexible. In a CCTV system, lighting has to be ‘designed in’ from the beginning if the best results are to be obtained. The type of lighting used, and the correct positioning, are vital to maximum security. Everyday ‘white light’ is actually a mixture of colours of different frequencies. CCTV is more receptive to ce
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Light LUX* DESCRIPTION 50,000 British summer sunshine 5,000 Overcast sky 500 Well lit office 300 Minimum for easy reading 50 Passageway/outside working area 15 Good main road lighting 10 Sunset 5 Typical side road lighting 2 Minimum security risk lighting 1 Twilight 0.3 Clear full moon 0.1 Typical moonlight/cloudy sky 0.001 Typical starlight 0.0001 Poor starlight *Metric unit of measurement of light. For more information contact the Sony Business Information Centre: 01932 816340 9
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Light Backlight Compensation It is also important to consider whether there are bright spots in the picture such as car headlights which can make identification of the vehicle registration or model impossible. This can also be a major problem where it is necessary to identify persons who are moving from bright daylight into artificial light. Very often this will result in the subject becoming an unidentifiable silhouette. The problem is exacerbated where bright spots in the images cause vertical
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Choosing a Camera The camera is the ‘eye’ of a CCTV system and at its core lies CCD (charge coupled device) technology. The CCD is comprised of about 500,000 light sensitive cells called picture elements (pixels) which convert the light falling onto its surface into an electrical signal. The performance of the camera, and ultimately the surveillance system, is more dependent upon the quality of the CCD than any of the other camera components. Currently, the popular formats are: n Half-inch Hi
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Choosing a Camera Sensitivity Colour cameras generally perform less well in low light than monochrome cameras, all other things being equal. Sensitivity is usually measured by reference to the lux level at which a camera can produce an image (see page 9). The lux valuation, although usually referred to as a metric unit of measurement of light, is very often applied subjectively to the ability of a camera to produce images. Comparisons based on the lux levels given by different manufacturers do n
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Choosing a Camera TURNER TO INSERT IMAGE (GLASS YOU SCANNED!). ADJUST PIC BOX IF NEC. Camera Resolution The higher the resolution the sharper the picture. The best resolution available at present for CCD cameras is approaching 750 horizontal lines (TV lines) (3-CCD, DXC-950P) and 500 vertical lines. Resolution is not necessarily the key decision point. Low resolution CCTV, which is usually lower cost, is often perfectly adequate and the final choice depends on the combination of camera features
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Choosing a Camera developed a range of Hyper HAD CCD Ineffective area solutions, the most popular of which include hybrid cameras that operate in colour when lighting is adequate, switching to monochrome as darkness falls. Some cameras operate in low light by reducing the number of frames Transfer register Hole accumulated layer captured to produce a brighter picture although Exwave HAD CCD this causes problems when there is movement within the image. Sony has developed a more radical approach b
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Selecting the Correct Lens The quality of the lens is vital in determining the quality of the final image. The basic optical characteristics of a lens are the focal length (in zoom lenses the focal length range) or angle of coverage, and the aperture range. We’ll look at these two characteristics together with a third important characteristic, the format. Focal Length (F) The focal length represents the distance from the optical centre of the lens to the point at which the image is in sharpest f
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Selecting the Correct Lens Aperture range The aperture is the clear opening in the centre of the lens that allows light to pass to the pick-up device. The aperture size is described in relation to the focal length (F). Thus the aperture is specified by an F number. If the lens has a focal length of 50mm and if the diameter of the clear opening of the lens is 25mm, then the lens is said to have an aperture of F:2 (50mm divided by 25mm = 2). A 50mm lens with an aperture of F:2 has the same light g
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Selecting the Correct Lens Another characteristic of lenses is the ‘depth of field’ (see illustration). If a lens is focused on an object there will be a certain area of sharp focus in front of and behind the object. The depth of this area of sharp focus is controlled by three factors: the focal length of the lens, the distance from the lens to the object and the F stop. Lens Format The lens format relates to the camera format, 1/3 inch, 1/2 inch, 2/3 inch. There are two lens mounting systems. M
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Which Monitor? A control room operator may be required to view images on a bank of monitors for prolonged periods. As the effectiveness of the surveillance system is crucially dependent upon the degree to which the operator can remain alert and avoid fatigue, correct monitor selection is vital. The monitor converts the video signal generated by the camera back into a visual image. It consists of a cathode ray tube (CRT) and a number of signal processing circuits. These circuits separate the ‘lum
