This free interactive 3D model shows how security cameras cover a building — each camera's field-of-view cone, the blind spots between them, and where coverage overlaps. Click any camera to inspect its lens, mounting, and the area it actually sees. It's a visual learning tool for security designers, CCTV integrators, facility managers, and students learning how camera placement, lens choice, and pixels-on-target shape real surveillance coverage.
The viewer turns abstract camera specs into the area each camera really covers:
• Field-of-view (FOV) cones — the angular area each camera sees, projected onto the floor and walls. • Blind spots — gaps below and between cameras where nothing is captured. • Coverage overlap — zones watched by two or more cameras for redundancy and hand-off. • Camera types — fixed cameras, pan-tilt-zoom (PTZ), and domes, each with different coverage behavior. • Mounting height and tilt — how position changes the footprint on the ground. • Pixels-on-target — whether a camera at a given distance has enough resolution to identify, recognize, or merely detect.
A camera's field of view is set by its lens focal length and the sensor size: a short (wide-angle) lens sees a wide but shallow area, while a long (telephoto) lens sees a narrow but far area. Coverage is never just "can the camera see the spot" — it's whether enough pixels land on the target at that distance to do the job, commonly measured in pixels per foot (or per meter). Designers aim for higher pixel density (identification) at entries and choke points, and accept lower density (detection) over open areas. Cameras are placed so their FOV cones overlap at critical lines, leaving as few blind spots as possible — especially directly beneath ceiling-mounted cameras, which is a common gap.
1. Drag to orbit the building, scroll to zoom, and pan to move around. 2. Click a camera to highlight its FOV cone and read its lens, type, and coverage specs. 3. Look for dark gaps (blind spots) and double-covered zones (overlap), and compare wide-angle vs telephoto cameras to see how lens choice trades width of view against pixels-on-target.
Field of view is the angular extent of the scene a camera captures, set by the lens focal length and the image sensor size. A wide FOV covers more area but spreads pixels thin, while a narrow FOV covers less area at higher detail. FOV combined with mounting height and tilt determines the actual footprint a camera watches.
Focal length sets how wide or narrow — and how near or far — a camera sees. A short focal length (wide-angle) gives a broad, shallow view good for area awareness; a long focal length (telephoto) gives a narrow, deep view good for capturing detail at distance. Choosing focal length is a trade-off between width of coverage and pixels-on-target.
Blind spots come from the area directly below ceiling cameras, gaps between non-overlapping FOV cones, and occlusions from walls, columns, shelving, or signage. They’re minimized by overlapping camera coverage at critical lines, adding cameras at corners and choke points, and verifying coverage in a model or site walk rather than assuming a spec sheet’s range.
A fixed camera always points one direction with a set FOV, so it reliably covers a defined area and is ideal for fixed coverage of entries and lines. A PTZ (pan-tilt-zoom) camera can move and zoom to follow activity or inspect detail, but it only sees where it’s currently pointed — so PTZs are usually paired with fixed cameras that provide constant coverage.
Pixels per foot (or per meter) measures how much camera resolution lands on a target at a given distance. It determines whether footage can identify a face, recognize a known person, or just detect that something is there — common design thresholds increase from detection to recognition to identification. Coverage only counts if the pixel density at that spot meets the goal for that location.