The formula to calculate the aperture area (A) is:
A=π(D2)2=π(n2f)2
Where:
Let's say the aperture diameter (D) is 50 mm, the focal length (n) is 100 mm, and the f-number (f) is 2. Using the formula:
A=π(502)2=π(1002×2)2
We get:
A=π×625=1963.50mm2
So, the aperture area is approximately 1963.50 mm².
Definition: The numerical aperture (NA) of a lens or optical system is a dimensionless number that characterizes the range of angles over which the system can accept or emit light.
Formula: NA=nsin(θ)
Example: NA=1.5sin(30∘)
Definition: The aperture of a lens is the opening through which light enters the camera.
Formula: A=fN
Example: A=502.8
Definition: Numerical aperture is measured to determine the light-gathering ability of an optical system.
Formula: NA=nsin(θ)
Example: NA=1.33sin(45∘)