IFOV Calculator
Compute angular resolution per pixel (mrad/px) for any CCTV camera + lens combination. Per EN 62676-4 DORI and NATO STANAG 4347 Johnson Criteria.
Inputs
2688×1520 · pixel pitch 2 µm
Results
IFOV
0.500 mrad/px
0.0286°/px
Pixels / degree
34.9
angular density
Sensor HFOV
67.8°
5.38 mm wide
Pixels on target
100
@ 10m, target 0.5m
EN 62676-4 DORI compliance at this distance:
Design the full system, not just the lens
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FAQ
What is IFOV in CCTV?
IFOV (Instantaneous Field of View) is the angular size of one pixel — measured in milliradians per pixel (mrad/px) or degrees per pixel. Smaller IFOV means higher angular resolution: each pixel covers a smaller part of the scene, so distant objects fill more pixels and become recognizable. Calculated as pixel_pitch ÷ focal_length.
How is IFOV used per EN 62676-4?
EN 62676-4 (DORI) defines four observation tasks (Detect/Observe/Recognize/Identify) at fixed pixel densities (25/62.5/125/250 px/m). IFOV converts those targets into camera+lens specifications: knowing required px/m at a given distance, you can solve for the lens focal length needed.
IFOV vs Johnson Criteria?
Johnson Criteria (used for thermal cameras per NATO STANAG 4347) requires a minimum number of pixels across a target dimension (1.5/6/12 cycles for Detect/Recognize/Identify on a person 0.75 × 1.8 m). IFOV gives those pixel counts at any distance. Lower IFOV = longer effective range.
Smaller pixel pitch = better range?
Smaller pitch means more pixels per object at distance — better recognition range. But smaller photosites collect less light, so low-light performance suffers (more noise). Modern sensors balance pitch against full-well capacity. Compare published min illumination (lux) when choosing.