I am trying to calculate the field of view of a camera from a given focal length and film width. I am using the following equation to do this.
FOV = math.degrees(2 * math.atan(filmWidth / (2 * focalLength)))
From reading online, this seems to be the correct way to calculate the value. It does not seem to be yielding the correct results though. Or at least not the results I am expecting.
The test data I have is as follows focalLength = 30.409 filmWidth = 1.089
expected FOV should be ~24.6
The formula above gives me 2.05164381552.
What am I missing here? Do I have something in radians when it should be degrees, or vise versa? Thanks for any help you can provide.