Know what you want to see. Knowing exactly what you want to see in the monitor and on recordings - both the scene and the quality - is the single best way you can prepare for.
- Avoid dummy cameras. While they may deter some problems, they also can create a legal liability by creating an expectation of safety when none exists.
- Put up signs. Highly visible signage that lets customers and employees know that they are being filmed can greatly increase the deterrent effect.
- Do not record audio. Most CCTV systems do not include audio monitoring for the simple reason that it is generally illegal. People in public places can be videotaped without their consent, but their voices can not.
- Buy for the right reasons. Using a high-tech solution to solve a low-tech problem can result in wasted money and effort. If you have vandalism problems in a parking lot, adding lights can be a far cheaper and more effective solution than installing cameras.Video Surveillance Introduction
From a single camera and monitor to complex video surveillance systems with hundreds of cameras, multiple operators, and digital recorders, closed circuit television (CCTV) systems can provide security for a wide range of businesses.
A good CCTV system can make your business safer, more efficient, and less prone to theft and accidents. Specifically, CCTV can provide many benefits:
The most basic CCTV setup would be a single camera connected directly to a monitor and a recorder to store the video. While a setup like this could help security in some cases, it is unlikely to be enough for most businesses. Most situations call for multiple cameras. In some cases, you may even want a moveable camera to cover a large area. This BuyerZone.com Buyer's Guide will help you understand what goes into a CCTV system and how to make a successful purchase.
Evaluating your CCTV needs
Before starting to compare systems or choose potential vendors, sit down and consider your CCTV needs carefully.
First, consider what you want to monitor. General comings and goings? Vehicles? Do you want to see faces, merchandise, crowds? Once you decide what you want to see, choosing components will become easier.
Next, decide what picture quality you need. Quality can refer to both how detailed the image is and how fast the frame rate is. Frame rate is simply a measure of how many individual pictures make up the video. "Full motion", what you see on television and on VHS tapes, is 30 frames per second, or fps. Most often, security systems record at slower rates, which result in more jerky-looking images but saves tape or hard drive space, allowing longer periods of time to be recorded.
Think about how your system will be monitored. Will you simply record at all times, and only review the tape when a problem occurs? Or will you have a dedicated employee watching for trouble? Also, with multiple cameras, you have the option of connecting each to its own monitor, or combining multiple images onto one monitor.
You should also decide whether your priority is to deter potential crimes or to catch perpetrators. Both can be important, but your priority will influence your purchasing decisions. If you are more interested in deterring certain activities, large, visible cameras are your best bet. Trying to catch criminals on tape without them being aware of it requires hidden cameras, which cost more both for hardware and for installation. If your monitoring target is internal, you run the added cost of having to hide and secure the recorder and monitor as well.
There are many technical terms and specifications that dealers will refer to when discussing security cameras as part of a CCTV system.
The basic technology behind most security cameras is the Charge Coupled Device (CCD). CCDs convert the images that come through the camera's lens into electronic impulses. CCDs provide a good combination of low price and quality picture for security applications.
Camera formats are measured in inches: most cameras fall between 1/4" and 1". This refers to the usable image size created inside the camera. For most security systems, a small size is fine - 1/4" or 1/3" cameras dominate CCTV sales. Larger formats do not necessarily result in better images, but can be advantageous in dimly lit situations since they are able to gather more light.
Color vs. black and white
Since prices have dropped significantly, many businesses today opt for color cameras over their black and white models. For security and evidence purposes, color cameras are better--sending security guards after "the man in the blue coat," for example, is much more difficult when you can not tell what color the coat is.
While black and white cameras can operate better than color cameras in extremely low light situations, most small to medium sized businesses use CCTV in well-lit indoor environments. In addition, many high-quality color cameras today can switch to black and white mode when necessary. Some vendors do not even sell black and white cameras any more.
Resolution refers to how detailed a picture the camera can see. The measurement to look for is horizontal TV lines (TVL). A normal CCTV picture is around 350 to 400 TVL, with high resolution getting up to 480 or 500. Upgrading a camera's resolution can cost as little as $50.
You need to make sure your entire system is capable of supporting that resolution. If your VCR records 350 lines and your monitor displays 400, the money you spent to upgrade to a camera with 500 lines is completely wasted. In the end, the small cost to upgrade your camera may be multiplied by the costs to upgrade other equipment.
Note: do not be impressed by pixel measurements in the hundreds of thousands. TVL is a more consistent measurement.
Signal to noise ratio (s/n) indicates how much "signal," or actual picture information, the camera transmits, as opposed to "noise," which comes across as static. A s/n ratio of 40db indicates that the signal is 100 times the noise, which results in an acceptable picture with some fine grain or snow. 30db results in a poor picture, and 60db produces an excellent picture with no static visible. Keep in mind that noise can be introduced by other components in addition to the camera.
Sensitivity to light is measured in lux. A sensitivity of 2 lux means the camera can see fairly well by the light of a 40W fluorescent bulb; 0.5 lux cameras can make out images outside on a dim night. Your needs will depend on the lighting in the area being filmed, but lux ratings should not be the most important aspect of your camera decision.
CCTV Camera Peripherals
Along with your CCTV camera, you need several peripherals to get your video surveillance system working.
The lenses you purchase should match the format of your camera: 1/4" lenses work best with 1/4" cameras. It is possible to use a larger format lens than the camera calls for, but it is not recommended.
You also need to decide what type of lens you need. Fixed focal length lenses offer only one set field of view and are the least costly. To change the resulting image, you need to switch lenses. Variable focal length lenses and zoom lenses offer greater flexibility, allowing you to adjust your image's field of view. Motorized zoom lenses, the most costly type available, give you the ability to control your cameras remotely. If you want to zoom out for general surveillance and in for detail when you spot suspicious activity, motorized zooms are the way to go.
If you will be using the CCTV camera outdoors, look for a lens with an automatic iris. As in the human eye, the iris of a lens is what controls the amount of light coming in to the camera. Automatic irises can significantly improve performance for outdoor cameras, where light levels vary considerably. However, you can save money and use a manual iris lens when the scene illumination never changes, for example in an illuminated store or office.
Pan, Tilt, Zoom
Surveillance Camera Monitors
Selecting a monitor for your CCTV system is a relatively minor decision, but there are a couple of important points to keep in mind.
First, make sure to purchase a monitor specially to handle the type of use it will receive. Televisions are not good monitors, since TVs are built to be on for a few hours per day, not the 8 to 24 hours per day they will endure. In some cases, computer monitors do make acceptable substitutes. Flat-panel LCD screens make great CCTV monitors for larger systems because they take up little space, have excellent resolution, and generate less heat than regular monitors.
As discussed earlier, make sure your monitor resolution matches your cameras. Buy a monitor with lower resolution and your camera's capabilities will not come through; buy one with higher resolution and you are throwing money away. And of course, make sure you buy color monitors if you opt for color cameras.
Also consider the size: a 9" monitor may be sufficient if the operator is sitting directly in front of it, but a 15" monitor is the smallest you should choose if you plan to combine images from multiple cameras onto one monitor. Merging multiple images onto one screen can be an effective way to save space, and appropriate if there is a dedicated employee who has the ability to zoom in on suspicious activity.
Security System Recorders
Recording is essential to the effectiveness of any security system. Without recording, you need to have an employee watching a monitor at all times - hardly a cost-effective solution. And even if you spot suspicious activity, without a recording, you have nothing to use in court.
Almost all CCTV systems include some sort of recorder to store the images the cameras capture. Only a few years ago, the universal solution was the familiar VCR. However, the introduction of digital video recorders (DVRs), which record onto hard drives instead of tape, has dramatically changed the situation.
DVRs offer so many advantages over VCRs that they have rapidly taken over as the CCTV recording solution of choice:
For businesses that do not want to constantly change tapes, DVRs are definitely the way to go. While security VCRs usually offer a time-lapse mode that lets them for long periods of time, the resulting images are not a good record of events - they record only one snapshot every eight seconds. To get higher quality, you need to change tapes every day or more often. DVRs, on the other hand, can record for weeks or even months.
DVRs are more considerably more expensive than VCRs, which is their only major drawback. However, the DVR prices have fallen considerably over the last year and will continue to do so. Already, low-end DVRs and high-end VCRs are in similar price ranges, and most manufacturers have stopped introducing new VCR models. Despite the increased cost, we recommend CCTV system buyers purchase a DVR whenever possible.
Choosing a DVR
The size of the hard drive will dictate how much you can record. On the low end, an 80-gigabyte (GB) hard drive will store about five to eight days of full-motion video from one camera. Most of the time you will not be recording full motion, so this is much more than it might seem. For most businesses, spending a little extra to get 120 or 240 GB is a worthwhile investment. Units expand up to 1.2 terabytes (1,200 GB), which can store many cameras' worth of data for long periods of time.
Replaceable hard drives are a cheap way to boost storage capacity. With some DVRs, you can buy additional hard drives for as little as $150 and swap them in and out as you need. This gives you the advantage of being able to store your data separately from the main security system.
You will also need to consider how many cameras you want to connect to the DVR. Keep your future expansion needs in mind - buying a higher-grade model to get more inputs and more storage space can save you considerable money in the future. The DVR will also function as a multiplexer, putting up to 16 cameras on one display and allowing operators to call up any one image for closer inspection.
Also, if you ever have to use your security images - in court or in other ways - you will need to be able to export the video. This is an important consideration: some systems let you create industry-standard .avi files, which can be played on any PC, and burn them to CD. Others only allow you to export proprietary formats that can only played on the same brand player. Most DVRs do offer the option to connect a standard VCR - this allows you to simply tape the digital recording onto a standard VHS cassette.
Choosing a VCR
The main feature to look for in a VCR is how many hours it can record: models range up to 960 hours on a standard tape. Remember, though, that these extended recording times result in fewer frames per second.
Be aware of the hidden and ongoing costs of VCRs. Buying, rotating, and replacing VCR tapes can be expensive and time consuming. Constant usage creates quite a bit of tape debris inside the machine, requiring expensive regular maintenance. And in addition, if you have multiple cameras, you will need a multiplexer - a separate piece of hardware that combines multiple video images into one - to avoid purchasing a separate VCR for each camera.
Connecting your CCTV System
There are several ways to connect cameras to the rest of your CCTV system.
The most common is standard coaxial cable, the same cable used to connect video equipment in your home. Some installers use unshielded twisted pair (UTP) cables, like the CAT5 cable used in many computer networks, because they can reduce interference caused by electrical currents. A simple switching device called a balun can be used to connect coaxial lines to UTP, so you can combine both in a single system. UTP is cheaper than coaxial cable, so for very long runs, this may be an advantage.
Casinos or banks with complex systems consisting of many cameras may want to upgrade to fiber optic connections. With this setup, bandwidth is considerably greater, allowing many signals to be carried on the same wire. In addition, security is improved because tapping a fiber optic line is very difficult to do without disrupting the signal.
There are situations where wireless is the way to go: connecting across a public street, for example, where digging a trench is not a practical solution. Wireless systems are also better suited for rural areas, where there are fewer potential sources of interference. In these cases, wireless transmitters can make expensive or potentially impossible installations feasible.
Installation of wireless systems requires specific expertise to diagnose problems and fine-tune the setup, so make sure your vendor is experienced with wireless setups if you choose to go this route.
Choosing a CCTV Integrator
The overall success of your CCTV system can hinge on the expertise of the installers who set it up. There are many important factors to take into consideration that require an expert understanding of lighting, optics, wiring, security, and more. In other words, your experience connecting your home TV to the DVD player does not mean you should set up your business security system!
In the CCTV industry, businesses typically buy from integrators or dealers. These vendors usually work with multiple manufacturers to offer a range of products, as well as installation and support. As with most business purchases, there are several key factors to look for when choosing a CCTV vendor.
Specific experience with businesses of your size and in your industry is also desirable: large warehouses may present problems that a vendor who specializes in small retail shops may not be prepared to address.
CCTV System Pricing
There are many components to a CCTV system: cameras, monitors, recorders, and cabling to connect the system. Add in the need for a quality installation, and it should be apparent that shopping by price alone is not a good approach. Some dealers will put together low-end packages to try to lure price-conscious shoppers - these systems suffer from lower quality, shaky reliability, and will not last for years and years the way higher quality systems will.
On the Internet, you can find complete CCTV packages of 4 to 16 cameras, including a monitor and VCR. Often they look like great deals - and most of the time, they are too good to be true. Low-quality components and a lack of support combine to create an offer that can do more harm than good to your business.
A very rough rule of thumb to use for pricing a complete, installed system is $500 to $1000 per camera, plus the cost of your recording device. This depends quite a bit on the types of hardware you choose and how you set it up - read on for a more thorough breakdown.
Cameras and lenses
Hidden cameras, concealed in everyday objects like clocks, smoke detectors, and calculators, run $200 to $400. PTZ cameras are far more expensive, running $1,500 to $5,000 for one camera and the controller. If you do not have an operator to run a PTZ camera, it is rarely worth the expense.
Remember that in most cases you are purchasing a camera without a lens, so there is more to spend before you get a workable system. Lens prices vary widely. Fixed focal length lenses can go for $100 to $300 depending on size and whether they have a manual or auto iris; automatic zoom lenses can be between $800 and $2,000.
Recording devices and peripherals
Housings can cost from $25 to $200, depending on the degree of protection they provide.
CRT monitors can go for $150 to $500 and flat panels range from $300 to over $5000. Both are heavily dependent on screen size.
However you may want to consider a maintenance plan. Having your vendor
regularly come in to clean and test your system can improve the overall
performance and ensure that any problems that do occur are caught quickly.