Enter the focal length (mm) and the distance between nodal points (mm) into the Minimum Focus Distance Calculator. The calculator will evaluate and display the Minimum Focus Distance.
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Minimum Focus Distance Formula
The following formula is used to calculate the Minimum Focus Distance.
MFD = FL * 4 + DN
- Where MFD is the Minimum Focus Distance (mm)
- FL is the focal length (mm)
- DN is the distance between nodal points (mm)
How to Calculate Minimum Focus Distance?
The following example problems outline how to calculate Minimum Focus Distance.
Example Problem #1:
- First, determine the focal length (mm).
- The focal length (mm) is given as: 3.25.
- Next, determine the distance between nodal points (mm).
- The distance between nodal points (mm) is provided as: 5.
- Finally, calculate the Minimum Focus Distance using the equation above:
MFD = FL * 4 + DN
The values given above are inserted into the equation below and the solution is calculated:
MFD = 3.25 * 4 + 17 = (mm)
Example Problem #2:
For this problem, the variables needed are provided below:
focal length (mm) = 7
distance between nodal points (mm) = 5.5
This example problem is a test of your knowledge on the subject. Use the calculator above to check your answer.
MFD = FL * 4 + DN = ?
