The diameter of a the back aperture of an objective lens is :
D = 2nf*sin(alpha) = 2f NA
The figure above is cited from this paper: "Simulation of an oil immersion objective lens: A simplified ray-optics model considering Abbe’s sine condition", Optics Express, Vol. 16, Issue 26, pp. 21170-21183 (2008)
D = 2nf*sin(alpha) = 2f NA
The figure above is cited from this paper: "Simulation of an oil immersion objective lens: A simplified ray-optics model considering Abbe’s sine condition", Optics Express, Vol. 16, Issue 26, pp. 21170-21183 (2008)