The formula to convert focal length to diopter (D) is:
\[ \text{D} = \frac{1000}{\text{F}} \]
Where:
A diopter is a unit equal to the reciprocal of the focal length of a lens (in meters), that describes the refractive power of that lens.
Let's assume the following value:
Using the formula:
\[ \text{D} = \frac{1000}{200} = 5 \text{ 1/m} \]
The Diopter (D) is 5 1/m.
