When designing CCTV camera systems, many people fail to consider what they want to see in the camera’s field of view. John Johnson, in his foundational work for the United States Army, developed what he called DCRI surveillance levels.
Detection: A target is determined to be in the camera’s field of view. Detection applications typically require wide-angle lenses. The lower the lens number, the wider the field of view. For example, a 4mm lens would have a wider field of view than a 12mm lens.
Classification: A target can be distinguished between an animal and an upright human.
Recognition: A human target is determined to be a threat based on the type of clothing and/or the equipment being carried.
Identification: A human target can be identified as a specific individual.
In order to obtain the proper field of view, the correct lens must be installed on the camera.
The best type of lens to use to ensure the proper field of view is obtained is the varifocal lens. There are many different types of varifocal lenses. Some are manual iris, and some are auto-iris lenses. A typical varifocal lens would be 5 to 50mm. For more information on lenses, visit different manufacturer’s Web sites. For example, try Bosch’s Web site at http://products.boschsecurity.us/en/TAMS/products/bxp/CATM40b8fcf5b76c79e176c117fb36cba772.
Monday, April 27, 2009
Friday, April 17, 2009
Why you should switch to megapixel cameras
I get a lot of people asking me, “Why should I switch to megapixel cameras?” If the camera/lens combination is configured properly, you may not need megapixel cameras. But they have some significant advantages. For example:
1. Dramatic forensic improvements over analog and IP VGA (more pixels equals more detail).
2. Instantaneous electronic Pan, Tilt and Zoom (PTZ with no mechanical moving parts).
3. Reduced camera counts on new installations (Some mega pixel camera manufacturers claim that one megapixel camera can sometimes replace up to 24 analog cameras).
4. Lower bandwidth requirements than VGA IP cameras when utilizing image-cropping feature.
Most manufacturers’ cameras have the ability to throttle back on the bandwidth demand. These cameras allow the same video quality but reduce the load on the network by limiting the bit rate. Another way to reduce the bandwidth demand is to utilize “edge recording.” The encoder has storage capacity built in and will only transmit across the network if an alarm is activated.
For the long run, you should plan on megapixel IP cameras. Maximize existing analog camera systems by using hybrid DVRs.
1. Dramatic forensic improvements over analog and IP VGA (more pixels equals more detail).
2. Instantaneous electronic Pan, Tilt and Zoom (PTZ with no mechanical moving parts).
3. Reduced camera counts on new installations (Some mega pixel camera manufacturers claim that one megapixel camera can sometimes replace up to 24 analog cameras).
4. Lower bandwidth requirements than VGA IP cameras when utilizing image-cropping feature.
Most manufacturers’ cameras have the ability to throttle back on the bandwidth demand. These cameras allow the same video quality but reduce the load on the network by limiting the bit rate. Another way to reduce the bandwidth demand is to utilize “edge recording.” The encoder has storage capacity built in and will only transmit across the network if an alarm is activated.
For the long run, you should plan on megapixel IP cameras. Maximize existing analog camera systems by using hybrid DVRs.
Monday, April 13, 2009
Placing CCTV cameras
Whether you use conventional analog cameras or IP megapixel cameras, you will not get your desired results unless you consider proper placement.
So how do you know where to place your cameras? Depending upon your particular industry or market, they should generally monitor two types of areas:
1. Choke points: These are spots where people or vehicles are traveling to get to places within a secure area. A camera strategically placed to cover a choke point will be able to capture either the vehicle type in a parking lot or identify a person who enters a building or room. Choke points can include hallways, doorways, driveways and parking garage exits.
2. Valuable assets: An asset is anything of value within your facility. This could be a drug closet in a school, a safe, a cash register or a swimming pool where liability issues are a factor. Any asset should be considered for camera placement. Other examples of assets could be trophy cases, valuable pictures, laptops and petty cash drawers.
So how do you know where to place your cameras? Depending upon your particular industry or market, they should generally monitor two types of areas:
1. Choke points: These are spots where people or vehicles are traveling to get to places within a secure area. A camera strategically placed to cover a choke point will be able to capture either the vehicle type in a parking lot or identify a person who enters a building or room. Choke points can include hallways, doorways, driveways and parking garage exits.
2. Valuable assets: An asset is anything of value within your facility. This could be a drug closet in a school, a safe, a cash register or a swimming pool where liability issues are a factor. Any asset should be considered for camera placement. Other examples of assets could be trophy cases, valuable pictures, laptops and petty cash drawers.
Friday, April 10, 2009
Advantages of hybrid digital video recorders
Many people ask, “Why should I go with a hybrid DVR instead of keeping my conventional DVR?”
If your goal is to plan for the future, and you have a limited budget, there are many benefits to a hybrid digital video recorder (DVR). Upgrading may make sense even if your current DVR is only a few years old and everything seems to be working just fine:
Benefit # 1: Most cameras are analog, and they have many years of service left in them. If you upgrade to a hybrid DVR, you can still use your existing cameras and then migrate to IP cameras slowly as your budget allows. Eventually, you can take advantage of the new technology by purchasing a new IP camera and installing it on your hybrid DVR system.
Benefit #2: Many schools have multiple buildings with unlimited bandwidth inside the building but limited bandwidth between buildings. The cost of adding additional bandwidth between buildings can exceed thousands of dollars per month. With a hybrid DVR, you can deploy the unit at a remote site close to the existing cameras and without bandwidth concerns between buildings.
Benefit #3: Hybrid DVRs have minimal setup and configuration time. Consequently, getting the system up with live video and recording is relatively quick and painless.
Benefit #4: Hybrid DVRs lower initial equipment cost and subsequently lower maintenance costs. Their total cost of ownership is less than that of systems using servers.
Benefit #5: Necessary training time is less than that of a pure IP solution. Most integrators will provide on-site training for administrators and operators. Usually, most end users will be able to operate and configure the system in a few hours, depending upon the manufacturer.
If your goal is to plan for the future, and you have a limited budget, there are many benefits to a hybrid digital video recorder (DVR). Upgrading may make sense even if your current DVR is only a few years old and everything seems to be working just fine:
Benefit # 1: Most cameras are analog, and they have many years of service left in them. If you upgrade to a hybrid DVR, you can still use your existing cameras and then migrate to IP cameras slowly as your budget allows. Eventually, you can take advantage of the new technology by purchasing a new IP camera and installing it on your hybrid DVR system.
Benefit #2: Many schools have multiple buildings with unlimited bandwidth inside the building but limited bandwidth between buildings. The cost of adding additional bandwidth between buildings can exceed thousands of dollars per month. With a hybrid DVR, you can deploy the unit at a remote site close to the existing cameras and without bandwidth concerns between buildings.
Benefit #3: Hybrid DVRs have minimal setup and configuration time. Consequently, getting the system up with live video and recording is relatively quick and painless.
Benefit #4: Hybrid DVRs lower initial equipment cost and subsequently lower maintenance costs. Their total cost of ownership is less than that of systems using servers.
Benefit #5: Necessary training time is less than that of a pure IP solution. Most integrators will provide on-site training for administrators and operators. Usually, most end users will be able to operate and configure the system in a few hours, depending upon the manufacturer.
Monday, April 6, 2009
Switching to an IP CCTV surveillance solution
Most companies want the best technology for their school districts. Unfortunately, budgets are strained from our current economy, and there is not enough money to upgrade to the latest devices. So do you plan for the future? When should you switch to a new IP solution?
One must answer some questions to see if you are a good candidate.
1. Are your existing cameras working properly?
2. Are your power and coaxial cables in good condition?
3. Are you satisfied with your coverage of existing cameras?
4. Are you looking to “future-proof” your security?
If you answered yes to all the questions above, then you should consider upgrading to a hybrid system. This will give you the benefits of “future-proofing” your security system by using your existing network with your existing cameras.
If you want to switch to an IP solution, consider these additional elements:
1. Do you have the IT staff available to support an IP solution?
2. What bandwidth is available for IP cameras?
3. Do you need better resolution in order to identify someone?
4. Are you satisfied with your coverage of existing cameras?
5. Do you want to improve your productivity and reduce the time required to investigate security issues?
Okay, you want to upgrade to the latest technology and you want to install an IP camera solution. However, you simply cannot afford to do it. What can you do to plan for the future?
Since most new technology evolves around the Ethernet standard, the key to planning for the future of your cameras (and all A/V equipment) is designing new construction around this standard. Develop a good relationship with your school district’s engineering firm and make sure they are on board with designing future buildings within the Ethernet standard. Eventually, when you are ready to make the switch, your buildings will be equipped to support your new IP camera solution.
One must answer some questions to see if you are a good candidate.
1. Are your existing cameras working properly?
2. Are your power and coaxial cables in good condition?
3. Are you satisfied with your coverage of existing cameras?
4. Are you looking to “future-proof” your security?
If you answered yes to all the questions above, then you should consider upgrading to a hybrid system. This will give you the benefits of “future-proofing” your security system by using your existing network with your existing cameras.
If you want to switch to an IP solution, consider these additional elements:
1. Do you have the IT staff available to support an IP solution?
2. What bandwidth is available for IP cameras?
3. Do you need better resolution in order to identify someone?
4. Are you satisfied with your coverage of existing cameras?
5. Do you want to improve your productivity and reduce the time required to investigate security issues?
Okay, you want to upgrade to the latest technology and you want to install an IP camera solution. However, you simply cannot afford to do it. What can you do to plan for the future?
Since most new technology evolves around the Ethernet standard, the key to planning for the future of your cameras (and all A/V equipment) is designing new construction around this standard. Develop a good relationship with your school district’s engineering firm and make sure they are on board with designing future buildings within the Ethernet standard. Eventually, when you are ready to make the switch, your buildings will be equipped to support your new IP camera solution.
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