Q:"怎么得到相关的数据的 最好能给出计算过程 谢谢大家"?
A: Given, EFL=120mm; f/#=2 --> EPD=60mm, y1=EPD/2=30mm; so refracted ray angle@singlet#04 is u4'=(EPD/2)/EFL=0.25 due to where the image principle plane P' is located.
total deviation angle from obj-space to ima-space is set to delta_u = 0.25; while delta_u = delta+u1 + delta_u2 + delta_u3 + delta_u4 = 0.25. Assuming delta_u1 = 0.25; then the sum of other three deviation angle would be delta_u2 + delta_u3 + delta_u4 = delta_u - delta_u1 = 0.0;
Since we knew the optical power distributions among all four singlet elements, each individual optical power or effective focal length can be calculated under the help the known PRTE equations.
That is where f1'/f2'/f3'/f4' come from.