Several factors need to be considered:
Overall Budget
Residential or Commercial Location
Type and value of material at Location
As with everything you get what you pay for. Cameras used for security have a method that is applied to the clarity of their field of view called DORI. The letters stand for Detect, Observe, Recognize, Identify - and the DORI specification is something one should critically review prior to any purchase. Each level increases the amount of detail and information that is able to be identified. These levels of detail increase from 12.5 pixels/meter (4 pixels/foot) to 1000 pixels/meter (305 pixels/foot).
Detect: where it is obvious what is being observed, a human or a vehicle in the field of view (FOV)
Observe: able to detect color of clothing, make of vehicle in FOV
Recognize: determine with a high level of certainty if an individual in the FOV is someone you’ve seen before
Identify: facial recognition level, without a shadow of a doubt a person can be identified by anyone who compares the facial characteristics in the FOV with a mug shot or other ID.
The DORI levels change dramatically depending on combinations of the following:
Type/Size of Object of interest
Distance to Object of Interest
Scene Lighting
Camera Resolution/Imager Size
Camera Lens Focal Length
Expected Purpose of Camera
Cameras intended to capture only observational data cannot be expected to produce inspection level information. For example, a camera chosen to view a parking lot will not be able to reliably capture license plates. The expected purpose of each camera of a system must chosen carefully to meet the expectation set once the system is commissioned.
An example of DORI in use would be as follows: a wide FOV low-light capable camera may be mounted at the roof of the building with an overview of the individuals parking their cars and walking to the entrance for Detect, while another camera is located under a soffit at the exterior building entrance for Observe, a 12mp fisheye on the ceiling in a lobby gather views of the entire room for Recognize, while another cameras with a narrow FOV at 6mp could be employed covering a single elevator or single stairwell opening for Identify. In this manner, we know who it was who went up in the building and may have an idea of the car they drove and where it was parked as well as the number of other individuals arrived or left with and if the others entered the building, who those individuals may be.
We design and implement high quality systems for data centers, corrections facilities, cannabis facilities, armory and other law enforcement facilities. If you’re looking for help without hype, feel free to contact me.