I am having some trouble finding a standard way to calculate the horizontal and vertical field of view of an image based on a set of initial input parameters.
I do have values for the following parameters:
- Horizontal Pixel Count: 1920
- Vertical Pixel Count: 1080
- Pixel Size (um): 3
- Horizontal Dimension (mm)
- Vertical Dimension (mm)
- Diagonal Dimension (mm)
- Focal length (mm)
- Working Distance (mm)
- Horizontal FOV (degrees)
- Vertical FOV (degrees)
- Diagonal FOV (degrees)
Edmund Scientific offered the following equation: where h is the horizontal sensor dimension, f is the focal length of the lens, and WD is the working distance. The Horizontal FOV is also in mm, for which I calculate for.
My problem is that the equation above gives me a different value than the following equation:
Horizontal FOV (mm) =
Working Distance (mm) * 2 * TAN(Horizontal FOV (degrees) / 2)
I'm looking to understand where my calculations may be going wrong and what a standard and accepted trig. equation would be to allow me to properly calculate the vertical and horizontal FOVs (in mm).
Solved: My problem in Excel was that when I was dividing by 2 in my TAN(HFOV/2), the 2 was in Radians and not degrees. Changing the formula to TAN(HFOV/degrees(2)) solved the problem.