Field of View

Field of view refers to the spatial area a camera lens can cover during image capture. It is typically described in three dimensions: Horizontal FOV (HFOV), Vertical FOV (VFOV), and Diagonal FOV (DFOV).

For body cameras, the size of the field of view directly impacts the scope of footage recorded, making it a crucial parameter for evaluating the completeness of video evidence.

1. Three Standard FOV Definitions

Abbreviation	Full Name	Description
HFOV	Horizontal Field of View	The angle covered horizontally by the lens; most commonly cited FOV metric.
VFOV	Vertical Field of View	The vertical angle coverage, which is heavily influenced by image aspect ratio.
DFOV	Diagonal Field of View	The total viewing angle across the lens diagonal; generally larger than HFOV and VFOV.

Example: If a body camera lens has a DFOV of 140°, its HFOV is typically around 115°–120°, and VFOV falls within 60°–70°, depending on the image aspect ratio.

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2. Common FOV Types and Applications

FOV Range	Description	Suitable Scenarios
≤ 90° (Narrow)	Focused view with clearer long-distance details	Facial recognition, targeted evidence capture
100°–130°	Wider coverage with minimal distortion	General law enforcement recording, routine patrols
≥ 140° (Wide)	High inclusivity with slight edge distortion	Indoor investigations, close-range confrontations

3. Trade-Off Between FOV and Distortion

Wider fields of view capture more area but tend to introduce edge distortion (barrel distortion). To balance coverage and image fidelity, many Shelleyes body cameras adopt a DFOV of 120° to 140°, providing comprehensive scene recording while minimizing image warping.

4. Selection Recommendations

Vehicle-mounted or helmet cameras: Wider FOVs enhance coverage in dynamic environments

Target identification applications (e.g., forensic evidence, facial capture): Recommended HFOV 90°–110°

Wide-area monitoring or patrol tasks: Recommended DFOV 120°–140° for broader situational awareness