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CHAPTER 1
Analogue CCTV
1.1 Analogue CCTV Quick Start
The commonest use of CCTV for wildlife monitoring is the camera bird box. Many get great pleasure from watching young birds in the nest, from blue tits to barn owls. For the novice, a bird box kit is the best way to start with CCTV. This section gives details of how to set up the sort of simple kit that is available from a wide range of suppliers.
1.1.1 Bird box – a simple introduction to CCTV
Figure 1.1 shows a basic CCTV set up.
Step 1. Buy a bird box kit (see Figure 1.2) consisting of:
Camera (fitted in the box).
Cables with RCA plugs.
Bird box.
Power supply adapter.
SCART to RCA adapter.
Step 2. Fix the bird box containing the camera to a suitable tree (see Figure 1.3) or other surface.
Step 3. Run the cable coming out of the bird box into your house. You may have to drill a hole in a wall or window frame. If you have power in a garage or shed, it is often possible to pass the wire past the door hinges or under the door. Cup hooks are good for keeping the wire out of the way (see Figure 1.4)
Step 4. Connect the camera power plug (red or black) to the power adapter, which should then be plugged into the mains.
Step 5. Connect the camera signal plug (yellow) to a monitor (also the white audio plug, if there is one). Some TVs have RCA sockets (yellow and white), but if your TV has a SCART socket you can connect to it using a SCART adapter. You can also buy monitors with RCA sockets.
Whenever you switch on the camera power and the monitor, you will be able to watch what is happening inside the box (see Figure 1.5).
If you connect a recorder (see Figure 1.6) as well as a monitor, you can record videos. Get into the habit of selecting and exporting the videos daily.
1.2 Basics of analogue CCTV
1.2.1 Introduction
1.2.1.1 What are CCTV cameras?
CCTV is short for closed-circuit television. CCTV cameras differ from the cameras delivering television programmes in that the signal is confined to a small area. CCTV cameras are either directly connected with wires to a television, monitor or recording device, or transmit the video signal wirelessly over short distances (generally less than 100 m). They are widely used for security surveillance, but are also suitable for monitoring wildlife. Unlike trail cameras, they film continually. The sensors in the camera usually detect both visible and infrared light. At night, infrared light-emitting diodes (LEDs) usually supply illumination.
Most CCTV cameras are analogue, which means they transmit a continuously variable signal, unlike digital IP cameras (Chapter 4) which transmit a digital signal consisting of individual pulses.
Standard analogue CCTV cameras are best used for portable CCTV (Chapter 5) where there is no mains power present. For situations where mains power is present, HD analogue cameras will give a high-quality signal, with HD-TVI (Chapter 3) being the newest form of HD analogue CCTV. HD-TVI uses the best technology from analogue and IP cameras to give superb quality at an affordable price.
1.2.1.2 What do they look like?
For the purposes of this book, the CCTV cameras described are those I have used for wildlife monitoring, but there is a huge range of cameras available, due to the size of the surveillance market.
Typical small camera
Figure 1.7 shows a typical bird box camera, which can also be used for mammal boxes and in confined spaces. The sensor will detect when light levels fall and will switch on the LEDs.
Typical connections for a small analogue camera
The connections for a small analogue camera are shown in Figure 1.8:
The red barrel connector carries power to the camera.
The yellow RCA connector carries the video signal from the camera.
The white RCA connector carries the audio signal (although not all cameras produce an audio signal).
Typical bullet camera
Small 'bullet' cameras, useful for larger outdoor subjects, are available in a wide range of sizes and types. Figure 1.9 shows a typical CCTV bullet camera with the main parts labelled.
Typical connections for a bullet CCTV camera
The connections for a small bullet camera are shown in Figure 1.10:
The barrel power socket delivers power from a power supply to the camera.
The BNC socket delivers the video signal from the camera.
1.2.1.3 Uses of CCTV cameras
Although the most popular use of CCTV cameras is to monitor activity in nest boxes, hedgehog boxes and bat boxes are also suitable subjects. The advantage of this use of CCTV is that once the cameras are set up, there is no disturbance to the wildlife. The main features of standard analogue CCTV can be summarised as:
Cheap cameras available.
Good for bird boxes and small mammal boxes.
Best for portable CCTV.
Night viewing possible with infrared illumination.
Image quality average to good.
1.2.2 Basic analogue CCTV setup
The basic components of a simple analogue CCTV system are shown in Figure 1.11.
1.2.2.1 CCTV component details
The camera
CCTV cameras consist of a lens which focuses light onto a sensor. The electronics converts the signal from the sensor to an analogue video signal. Audio is sometimes available as well. The details are shown in Figure 1.12.
Wildlife CCTV cameras often need an infrared LED light source as many UK mammals are nocturnal. During the day, sunlight is reflected from the subject and the camera gives a colour image. If light levels are very low, the camera uses its own infrared light source and this gives a black and white image.
A CCTV camera needs power, usually in the form of 12 volts DC. Cameras kits supply a power adapter which can be plugged into the mains and which converts AC mains voltage to 12 volts DC for the camera.
There is a huge range of CCTV cameras to choose from. In practice, using a wildlife camera supplier is advised initially, especially as they have suitable connection kits and suitable outdoor cameras. A camera with the highest resolution (number of TVL lines) is advised.
Monitor
A monitor is required to view the images. This can be a TV or a separate monitor (such as used for a PC). The monitor is also required while setting up the camera, to make sure that the camera displays the area you wish to observe. The cable from the camera carrying the video (and in some cases audio) signal is plugged into the monitor.
Recorder
A recorder is required only if you wish a permanent record of what you see. The best recorders have motion detection and only record if the image from the camera shows movement. Note this is different from trail camera motion detection as that depends on changes in heat, rather than actual motion as here.
PC video capture
Instead of a recorder and monitor, a PC can be used. This requires a capture device to convert the analogue video signal to a digital form for the PC. Capture devices often come with software which allows viewing of the video directly on the PC. If more than one camera is viewed, this method becomes more complex, requiring a capture card to be connected inside the PC.
Software
One advantage of connecting cameras to the PC is that you can use software to control the recording. Motion detection recording is usually found on recorders, but using software on the PC gives much more flexibility in setting up the recording parameters. iCatcher is suitable software, and for one or two cameras is not expensive. It is not straightforward to set up, but support is available from the authors of the package (iCode).
1.2.2.2 Connections
Details of how to connect a simple CCTV system from a kit are shown in Figure 1.13. Connecting up the system is straightforward with a kit. The connectors are colour coded and the connectors match in type or have suitable adapters. Most kits supply an audio connection (usually white) but this is not always needed as not all analogue CCTV cameras have sound.
A long cable connects the camera outside to the power source and recorder inside. Keeping the cable as short as possible is advised as this gives better video quality. Cameras can be connected via the cable directly to any TV or monitor that has the correct sockets, and most kits supply adapters.
Connecting to a recorder
Figure 1.14 shows a block diagram of a CCTV system with a recorder. If you use a recorder, the video cable is connected to the recorder input, often called 'AV in', and another cable is connected from the video 'AV out' to the monitor. The video files can usually be transferred to a USB drive and played on a PC. A recorder with a built-in monitor makes life easier but increases the cost.
Connecting to a PC
A camera cannot be connected directly to a PC as the analogue signal has first to be converted to digital. Small video capture devices are easily obtained and these connect to the camera cable at one end, and the PC USB port at the other (see Figure 1.15). The devices come with a disc so that viewing software can be installed on the PC.
1.2.2.3 Weatherproofing
It is important to find out if your chosen model of CCTV camera is waterproof, weather-resistant or not suitable for outdoor use. The more expensive type of CCTV camera used for general surveillance is usually weatherproof, but this is not always the case for nest box and other cameras, so care is required when buying. Cameras described as weather-resistant can usually withstand some rain, but for heavier bursts, a roof or three-sided box may be advisable (see Figure 1.16).
The better cameras use an IP rating where IP stands for International Protection marking. The most suitable rating for cameras are IP65 to IP68. The first digit, 6, means it is dust tight, the second digit describes how much water it can withstand. IP65 means the camera can withstand jets of water and IP68 means the camera can be submerged. Further information from the camera manufacturer will be required as to how deep that submersion can be.
Thus IP65 to IP68 will be waterproof in heavy rain.
1.2.2.4 Power delivery
All CCTV cameras need a power source. Most CCTV cameras are connected to mains power (wired), but some are wireless and this affects the way in which power is delivered to the camera.
Wired cameras In a wired system there is usually a wire for power attached to the video wire and this second wire has one end connected to the camera. This means that either the camera must be close to the location of the recorder or display device, or long cables will be required. The power is delivered using an adapter which is plugged into the mains and is connected to the other end of the power wire.
Wireless cameras In a wireless system, although the signal from the camera is transmitted through the air, power is still required by the camera. This can be supplied via a cable, thus removing the advantage of wireless systems, or by a battery, which will need regular recharging.
1.2.2.5 Cost
The cost of a CCTV camera depends on its size and signal quality. Small nest box cameras can cost from £20 to £100, with the more expensive, high-resolution cameras costing £50 to £200 and upwards.
The image quality of a camera is described in term of TV lines (TVL). An explanation of this can be found in the section 2.5.1. Cameras with 600 TVL are standard analogue cameras and are not expensive. Those with 1,000 TVL are described as high-resolution and are a little more expensive.
1.2.2.6 Examples of use
Bird boxes (small cameras)
Bird boxes with built-in cameras are the easiest way to start with CCTV, but kits vary greatly in quality. For an easy start, make sure the camera is already fixed into the bird box and attached to the cable. That way, all you have to do is drill a hole to bring the cable from the outside to inside, then connect to a power supply, TV, monitor or recorder. Some boxes have visible lights as well as the infrared lights on the camera. The visible lights should have an in-built controller which switches off the power to the visible lights when it is dark, thus ensuring birds are not disturbed at night when resting.
Once you are familiar with the setup of nest box systems, it is not difficult to make your own bird box camera system. (See section 2.12.1 on making a camera bird box.) Be aware that most of the small cameras used in bird boxes and mammal boxes are not waterproof, so cannot be used outdoors without some protection.
Mammal boxes (small cameras)
It is possible to buy kits for hedgehog boxes and bat boxes, which have an almost identical setup to that for bird boxes, the only difference being the shape of the box and the positioning of the camera. It is not difficult to make your own mammal box and great fun can be had making boxes for mice, voles and shrews and watching their behaviour. Wooden boxes look good from the outside, but it is much easier to use plastic boxes, which have the additional benefit of being watertight.
The cameras with kits tend to give lower-quality images (see Figure 1.17). The quality of the image depends on several factors: camera type, camera quality, camera resolution, cable type, connections and lighting. Once the initial thrill of seeing 'your' birds or small mammals has passed, you may want to improve image quality. Ways to do this are described in section 7.1, and an example is shown in Figure 1.18.
1.2.2.7 Modes of use
Colour videos by day (larger cameras)
Many UK mammals, such as deer, foxes, otters and badgers, are nocturnal, but, with the possible exception of badgers, most can be found out and about during the day if they think there are no humans (or dogs) around. Setting up a video camera in an area where mammals are likely to appear can be fruitful and can supply colour videos. However, unless you are lucky enough to have such areas on your doorstep, you may have to set up in a remote area, and trail cameras or portable CCTV systems will be required. You may have seen the result of CCTV cameras on television wildlife programmes, but you are not usually shown the kilometres of cables behind the scenes. A recent portable system behind the scenes of such a programme used a fuel cell 'battery' to supply power. Fuel cells can cost upwards of £5,000. The chapter on portable CCTV shows how a portable CCTV system can be achieved at relatively low cost.
Infrared videos by night
For those mammals that are nocturnal, most videos will be taken at night, with light supplied by the infrared LEDs on the camera. Additional light sources can be added if power is available. These can be white light from LED floodlights or infrared from illuminators. The clarity of the image is generally improved with additional light. However, good-quality CCTV cameras benefit from a good source of light provided by their integral infrared LEDs (see Figure 1.19).
1.3 Videos
Bird box
Figure 1.20 shows an image from a video of two nestlings in a camera bird box being fed. Because the camera is small, low resolution and does not have professional standard cables, the image quality is not as good as it could be, but the first video is always an achievement for the novice.
CHAPTER 2
Advanced CCTV details
This chapter can be used as a reference. You may wish to skip it and come back to it when you want to delve deeper.
Once a basic system has been setup using a cheap kit, and you are familiar with its use, you may wish to improve the quality of your images. This chapter delves into CCTV more deeply and gives details on how to improve video quality.
2.1 Introduction
Cables are required to carry the video output from the camera to the monitor or recorder. If the camera has sound capability, a separate lead carries the audio signal. For basic CCTV systems, the video signal is carried by a basic cable with yellow RCA connections, and the sound cable connections are white, although not all cameras have a sound output.
For professional CCTV systems more advanced cables and connectors are used to give a higher quality of video, although audio is less common.
In most cases, CCTV also uses wires to transfer power to the camera. Although most cameras can be powered by battery, this can be inconvenient for continuous use, although necessary for portable CCTV.
Choice of cables and connectors has a major influence on video quality.
2.2 Digital and analogue
CCTV cameras today use similar sensors to those used in digital cameras and these sensors produce a continuously variable (i.e. analogue) signal. Digital still cameras convert the analogue signal from these sensors to a digital signal consisting of individual pulses, whereas, with the exception of IP cameras, CCTV cameras remain analogue.
If the signal from an analogue CCTV camera is transmitted to a recorder (as well as a monitor), the analogue signal is converted to a digital signal by the recorder and stored on digital media, usually an SD card or a hard disc.
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Excerpted from "CCTV for Wildlife Monitoring"
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Copyright © 2016 Susan Young.
Excerpted by permission of Pelagic Publishing.
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