Which factors change the field of view (FOV) of an infrared camera?

• A. Lens
• B. Focal length
• C. Detector resolution
• D. Lens, focal length and detector resolution

Answer: (D)

Field of view is the angle of the scene the camera can image. It’s set by the combination of the lens and the detector size: a shorter focal length or a larger detector makes the field of view wider, while a longer focal length or a smaller detector narrows it. Detector resolution matters because it determines how many pixels sample that angular field; higher resolution lets you resolve more detail across the same field, while lower resolution reduces how densely the field is sampled. While the physical angular extent comes from the lens and sensor size, how that field is used and represented depends on the detector’s resolution, so all three factors can influence the practical field of view.