ATTAINING THE REQUIRED LENS IN MILLIMETERS
(without using a Field of View Calculator)
H = Horizontal area (in feet) V = Vertical area (in feet) OD = Object Distance from lens and
viewing area (in feet) F = Required Focal Length (in
millimeters)
1/3"
1/2"
2/3"
F =4.8 X OD
H
F =6.4 X OD
H
F =8.8 X OD
H
F =3.6 X OD
V
F =4.8 X OD
V
F =6.6 X OD
V
H =4.8 X OD
F
H =6.4 X OD
F
H =8.8 X OD
F
V =3.6 X OD
F
V =4.8 X OD
F
V =6.6 X OD
F
Example: Using a 1/3" camera, you want to see a 12 foot horizontal field of view
from 25 feet away.
