How to Position Video Surveillance CamerasBy: John Honovich, Published on Jan 14, 2009
This report shares best practices for positioning surveillance cameras and is based on standards I developed as an integrator.
Figuring out the right number, placement and views of cameras can save significant money and provide a much more effective system. This is a critical element regardless of using IP or not. Moreover, this is an important skill set that IT techs coming into video surveillance must ensure they develop.
Here are the 4 steps I recommend:
- Determine Places for Cameras
- Determine Camera Types
- Determine View of Cameras
- Verify with Customer
Places for Cameras
Cameras should be placed in two types of places:
- Where there is an asset you are trying to defend
- Where there is a choke point toward an asset you are trying to defend
You place cameras looking at assets because you want to record anything adversarial that might occur to the asset: theft, destruction, tampering, etc.
You place cameras at choke points so (1) you can get notice as soon as possible of a potential threat and (2) so you can get a clear shot at the person (or vehicle's) characteristics.
This works the same whether it is a military base or a grocery store. Obviously the assets and location of choke points differ but these guidelines remain.
For example, at a convenience store, the assets are typically the cash register, safe, liquor section and stockroom. You would normally expect a camera to be placed to cover each of these assets. In addition, at a convenience store, the choke points are usually the front entrance (customer entrance) and sometimes the back/service entrance. You would generally expect to see cameras covering these locations.
Camera Type Selection
You have 3 general types of cameras to choose from:
- Fixed cameras: the view is locked on to a specific area
- Mechanical PTZs: the view can be manually adjusted by an operator over great distances but the system can only record the current area viewed
- Panoramic cameras: the view can be manually adjusted by an operator over small area and the the system can record the entire area covered
Fixed and mechanical PTZs are the two traditional options. Panoramic cameras are an emerging category and are almost always megapixel IP.
Here are guidelines in choosing:
- Use fixed cameras if there is a very specific area of interest and you do not have an operator watching in real time
- Use PTZ cameras if there is a large area of interest (more than 200 square feet/25 square meters) AND you have an operator watching in real time
- Use Panoramic cameras if you have a small area and you do not have an operator watching in real time.
Views of Cameras
Picking the general location of cameras is only half of the solution. For example, you know you want to protect the safe or cover the front door.
Additionally, you need to make sure that the camera is set up so it properly captures the target. It matters if the camera is too high or too much to the left or right. It also matters, it the camera is zoomed out too much so that you cannot make out detail or the opposite that it is zoomed to far and you miss part of the person or object in question. Such issues happen all the time and is a primary concern of integrators.
Technically, you need to determine and optimize the Field of View (FoV). Below is a good webcast on Field of View from Peter Brissette:
Verify with Customer
Before you install any cameras, you should prepare and provide the following documentation to the security manager:
- Take a photo of the approximate FoV of the camera
- Take a photo of the place where you plan to mount the camera. Mark the exact spot on the photo
- Prepare a map of the facility. Mark the location of each camera on the map
- Submit all of this in a report
This may sound time consuming and wasteful but I think it is critical (1) to ensure that the objectives are met and (2) to eliminate re-work and changes after installation.
Without pictures and plans, it's very hard to imagine how exactly cameras should be placed. It is also very easy for misunderstandings to occur ("I thought you were going to mount in on this side rather than that side", etc.).
A careful planned and documented design is a key tool in deploying optimized video surveillance solutions