Wolfram|Alpha

Computing...

Input information:

numerical aperture |  \ndiameter of aperture | 30 mm  (millimeters)\nfocal length | 50 mm  (millimeters)


Result:

numerical aperture | 0.2873


Equation:

NA = sin(tan^(-1)(D\/(2 f))) |  \nNA | numerical aperture\nD | diameter of aperture\nf | focal length