WIDE
Distance from 2 inches to 1 foot
Equivalent FOV: example 6 inches distance has 6 inches quare FOV
Medidum
Distance from 2 inches to 1 foot
Half size FOV: example 1 foot distance has 6 inches quare FOV
Narrow
Distance from 2 inches to 6 inches
1/3 fov sizes: example 6 inches distance has 2 inches quare FOV
Long range narrow
Distance from 3 inches to 5 feet
1/3 size FOV: example 5 feet distance has around 1.5 feet FOV