[求助]关于Effective focal length的问题 [复制链接]

  ZEMAX中priscription data会给出系统的许多有用的数据，其中包括effective focal length的数据和主平面位置的数据。但是我发现直接给出的effective focal length数据和根据其定义结合主平面的数据算出来的结果不一致，这时怎么回事？ lA4TWU (]  
一下是我的Prescription Data数据： ?^`fPH=  
GENERAL LENS DATA: 6LabFX@{&  
d\r-)VWSr"  
Surfaces                :                3 Fj"/jdM  
Stop                    :                1 EIPXq  
System Aperture         : Object Space NA = 0.12 pB7^l|\]  
Glass Catalogs          : Schott t~8H~%T>v  
Ray Aiming              : Paraxial Reference, Cache On 3h}i="i  
X Pupil shift          :               0 MXDUKh7v3  
Y Pupil shift          :               0 'p[B`Ft3F  
Z Pupil shift          :               0 f|~X}R  
Apodization             : Gaussian, factor =   1.00000E+000 |AS<I4+&  
************************************************************* .=9d3uWJ/  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) er3`ITp:dp  
Effective Focal Length  :        1.639158 (in image space) fm q(!  
*************************************************************
4^:$|\?]  
Back Focal Length       :       -1.061568 Q&/WVRD  
Total Track             :           4.318 3{|]@ L  
Image Space F/#         :        3.417255 O9AFQ)u   
Paraxial Working F/#    :        2.950535 s5)y%,E  
Working F/#             :        2.961912 > iYdr/^a  
Image Space NA          :       0.1670788 ^$[iLX  
Object Space NA         :            0.12 }^^c/w_  
Stop Radius             :       0.2398355 >B;KpO"+m  
Paraxial Image Height   :               0 [.&n,.k  
Paraxial Magnification  :               0 |f(*R_R  
Entrance Pupil Diameter :       0.4796709 ^sqzlF  
Entrance Pupil Position :               0 %.HLO.A  
Exit Pupil Diameter     :        2.511155 =T1Xfib  
Exit Pupil Position     :        7.420935 q4,/RZhzh  
Field Type              : Angle in degrees WuTkYiF  
Maximum Field           :               0 8]rObT9>  
Primary Wave            :            1.31 G#A6<e/  
Lens Units              :   Millimeters VmRfnH"  
Angular Magnification   :               0 DhD##5a  
h.NCG96S  
Fields          : 1 .
}:*tvot  
Field Type: Angle in degrees V/zmbo)  
#        X-Value        Y-Value         Weight gAf4wq  
1       0.000000       0.000000       1.000000 @jrxbo;5  
@a,=ApS"  
Vignetting Factors :[0)Uu{  
#       VDX       VDY       VCX       VCY       VAN RL fQT_V  
1  0.000000  0.000000  0.000000  0.000000  0.000000 ^dE[ ;  
p"j&s  
Wavelengths     : 1 14*6+~38m&  
Units: Microns [70 5[  
#          Value         Weight QS1lg  
1       1.310000       1.000000 )<qL8#["U  
^Y5I OX:  
CARDINAL POINTS: |$~]|SK  
wSPmiJ/!  
Object space positions are measured with respect to surface 1. +wQ}ZP&  
Image space positions are measured with respect to the image surface. [JV?Mdzu  
The index in both the object space and image space is considered. $\bVu2&I  
B+Ft >  
                          Object Space         Image Space (@;^uVJP  
W = 1.310000 (Primary) R~fk/T?  
************************************************************ u]i%<Yy89  
Focal Length          :           -1.639015            1.639015 bm4Bq>*=U  
************************************************************ xvomn`X1  
Focal Planes          :            0.313078           -1.159568 Wu(^k25  
Principal Planes      :            1.952094           -2.798584 =E^/gc%X  
Anti-Principal Planes :           -1.325937            0.479447 gQJLqs"F  
Nodal Planes          :            1.952094           -2.798584 CF@*ki3X  
Anti-Nodal Planes     :           -1.325937            0.479447 owb+,Gk(  
yrl7  
我用*号，标出了需要注意的地方，请高手指教！

各位指点一下吧，自己顶起来！

帮顶！！！！！！！！！！！！！！1

等待高手帮忙吧 我也不会!

看的我头晕了,可能是感冒的缘故吧,以后有机会再探讨

我也不会先看看再说!~

慢慢理解