Search
Menu
DataRay Inc. - ISO 11146-Compliant Laser Beam Profilers
Photonics Dictionary

t number

The equivalent f number of a fictitious lens that has a circular opening and 100 percent transmittance, which would give the same central illumination as the lens being considered:



where EFL is the equivalent focal length, A is the area of the entrance pupil, and t is the transmittance of the lens system. For an unobscured system:

We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.