How many security cameras does my facility need?
The number of cameras depends on what each camera must do, not on square footage. For every area, decide whether you need to detect that someone is there, observe what they are doing, recognize a known person, or identify a stranger. Each goal needs a different image detail.
The international standard IEC 62676-4 sets guideline pixel densities for these goals: about 25 pixels per meter to detect, 62 to observe, 125 to recognize and 250 to identify. Designing to those targets prevents both blind spots and wasted cameras.
How long should businesses keep security camera footage?
Many commercial facilities keep video for 30 days, but the right retention period comes from your own policies, industry regulations, insurance requirements and legal counsel. Some regulated environments require longer retention for specific cameras.
Retention is one of the biggest drivers of storage cost, so set it per camera group rather than one number for the whole site.
How much video storage do I need?
Video storage depends on camera count, resolution, frame rate, compression codec, scene activity and retention days. Modern H.265 compression typically needs much less storage than H.264 for the same image quality, and recording on motion or at lower frame rates in quiet areas reduces it further.
A proper design calculates bitrate per camera and adds headroom for growth and drive redundancy. Undersized storage is the most common reason footage is missing when an incident happens.
Is cloud-managed video better than an on-premise VMS?
Cloud-managed video suits multi-site organizations that want simple remote access and centralized updates. An on-premise video management system (VMS) suits sites with high camera counts, strict data-residency rules or limited upstream bandwidth.
Hybrid designs that record locally and manage from the cloud are increasingly common. Compare total cost over five to seven years, including licenses, storage and bandwidth.
What does NDAA compliance mean for security cameras?
NDAA compliance means avoiding video surveillance equipment and components from the manufacturers named in Section 889 of the FY2019 National Defense Authorization Act. These are Hikvision, Dahua and Hytera for video and radio equipment, plus Huawei and ZTE for telecommunications, and their subsidiaries and affiliates.
Federal agencies, and contractors doing business with them, are restricted from these products. Many universities, utilities and private enterprises adopt the same standard as policy.
When do wireless security cameras make sense?
Wireless video links make sense for large outdoor sites such as yards, lots and campuses, where trenching conduit to each pole would be slow and expensive. Point-to-point and point-to-multipoint radios carry camera traffic back to the recording system, and cameras still need local power.
At Palletized Trucking's 30–50 acre Houston freight facility, a wireless design expanded coverage with an estimated 20–30% cost saving compared with a traditional wired build.
Do PTZ and outdoor cameras need special Power over Ethernet?
Often yes. Standard PoE (802.3af) delivers up to 15.4 W at the switch, and PoE+ (802.3at) up to 30 W. Many PTZ cameras, cameras with heaters or blowers, and multi-sensor cameras need 802.3bt (PoE++), which provides up to 60 W or 90 W.
Check each camera's power class against the switch's total PoE budget. A switch that can't power every port at full load will drop cameras in winter, when heaters turn on.
Are video analytics worth it?
Video analytics are worth it when they cut down the footage people have to watch. Common uses are line-crossing and loitering alerts on perimeters, vehicle and person search across recorded video, and occupancy counts.
Tune analytics during commissioning and review false alarms in the first weeks. Poorly tuned alerts get ignored.
