To ensure comprehensive coverage and avoid missing critical footage—whether it’s of theft, accidents, or unauthorized access—choosing the right IP cameras and their placements is crucial for maintaining a secure environment. This guide outlines how to conduct a site survey, select appropriate cameras, and determine the right resolution, lens, and placement.
Developing Your Site Survey
A thorough site survey is key to ensuring complete coverage. The diagram below aids in identifying optimal camera placement and estimating lens angles. Triangles on the diagram represent camera coverage areas.
When creating your diagram, consider the following:
- Area Coverage: How extensive is the area you need to monitor?
- Detail Requirements: What level of detail do you need? Is it sufficient to identify people, or do you need to recognize their faces?
- Day/Night Operation: Will the cameras need to function effectively both during the day and at night?
- Background Lighting: Will the camera be pointed at a brightly lit background, such as a lobby with large windows?
- Alert Notifications: Do you need the system to alert you to specific conditions?
After drafting your diagram, you can select the appropriate cameras and lenses based on these considerations.
Selecting the Right Surveillance Camera
Different IP cameras are designed for various applications. Using an indoor camera outdoors, for instance, would be impractical and costly. Choose cameras based on specific requirements:
- Low Light Performance: For low-light conditions, select cameras with good low-light performance.
- Panoramic and PTZ Cameras: Panoramic cameras offer 360-degree views, while PTZ (Pan-Tilt-Zoom) cameras with long-range lenses are suitable for viewing distant objects like license plates.
Don’t overlook the importance of the video recording and management system, which is integral to your surveillance setup.
Camera Resolution
Choosing between 2-megapixel and 8-megapixel IP cameras depends on two factors:
- Detail Required: What level of detail is needed? For example, do you need to identify faces or just recognize the type of vehicle?
- Field of View: How wide a view do you need?
Understand your objectives first. For instance, identifying a person’s face requires high resolution, while viewing a crowd requires less detail. Objectives are categorized under the DORI framework:
- Detection: Alert if motion is detected, regardless of object type.
- Observation: Allows for identifying features like clothing color or general appearance.
- Recognition: Identifies known individuals based on clothing or behavior, and can recognize license plates.
- Identification: Provides enough detail to recognize an unfamiliar face.
Resolution and Field of View
Once the required pixel count for object details is determined, assess how many objects can be seen simultaneously within the field of view. Higher resolution allows for a wider field of view. IP cameras typically range from 2 to over 12 megapixels.
Choosing the Right Lens
The lens affects the distance and magnification of objects:
- Lens Angle: A smaller lens angle offers higher magnification. For instance, a camera with a 33-degree lens can read a license plate from 39 feet away, while a 26-degree lens can do so from 66 feet away.
- Lens Specifications: Verify lens specifications to ensure the camera and lens meet your needs.