之前回家了，好久没登了，这个我也不知道 rQ@ , Y"
在modern lens design英文第一版中329页中有个注释提到了这个。看来是用来计算higher-order contributions的。 FzFY2h;n]B
{(7C=)8):
The fifth, seventh, etc., orders may also be computed from paraxial raytrace data. ` {ou4H\
Buchdahl develops specific equations by which the higher-order contributions may be sW@4r/F>:D
calculated. The equations for the fifth-order contributions are very complex and are usu- (*^_ wq-;
ally calculated as part of a computer optical software package
