[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？ Nk9=A4=|  
一下是我的Prescription Data数据： ZSu.0|0#  
GENERAL LENS DATA: O}"oz3H  
{\5(aQ)Vi5  
Surfaces                :                3 Lip#uuuXXN  
Stop                    :                1 Q# hRnM  
System Aperture         : Object Space NA = 0.12 _&l8^MD  
Glass Catalogs          : Schott /[TOy2/;%b  
Ray Aiming              : Paraxial Reference, Cache On i\CA6I  
X Pupil shift          :               0 ^ =C>  
Y Pupil shift          :               0  ]~;*9`:  
Z Pupil shift          :               0 lfAy$qP"}  
Apodization             : Gaussian, factor =   1.00000E+000 <.)=CK  
************************************************************* Yh95W  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) ~);4O8~.  
Effective Focal Length  :        1.639158 (in image space) yu6~:$%H  
************************************************************* x/<ow4C  
Back Focal Length       :       -1.061568 >n,_Aj c  
Total Track             :           4.318 PzPNvV/o  
Image Space F/#         :        3.417255 k^oSG1F  
Paraxial Working F/#    :        2.950535 .OJGo<#$f  
Working F/#             :        2.961912 ]-t)wGr  
Image Space NA          :       0.1670788 uUfw"*D  
Object Space NA         :            0.12 2xN7lfu1RB  
Stop Radius             :       0.2398355 FJ84'T\~  
Paraxial Image Height   :               0 E6GubU  
Paraxial Magnification  :               0 _-fLD  
Entrance Pupil Diameter :       0.4796709 |va@&;#wf  
Entrance Pupil Position :               0 D#<y pJR  
Exit Pupil Diameter     :        2.511155 $+PioSq  
Exit Pupil Position     :        7.420935 x[t?hl=:  
Field Type              : Angle in degrees '`upSJ;e  
Maximum Field           :               0 vGyQ306  
Primary Wave            :            1.31 XI`_PQco  
Lens Units              :   Millimeters mywxV  
Angular Magnification   :               0 cPtDIc,  
c&T5C,]  
Fields          : 1 ;,-)Z|W  
Field Type: Angle in degrees (~G*'/)  
#        X-Value        Y-Value         Weight bpsyO>lx/  
1       0.000000       0.000000       1.000000 dFg&|Lp  
^U~Er'mT  
Vignetting Factors MLr L"I"  
#       VDX       VDY       VCX       VCY       VAN DSs/D1mj&  
1  0.000000  0.000000  0.000000  0.000000  0.000000 NATi)A"TZ  
o2(w  
Wavelengths     : 1 ^RnQX#+  
Units: Microns _,^f,W
O~  
#          Value         Weight wp:$Tqa$  
1       1.310000       1.000000 !}c D e12  
8!v|`Ky  
CARDINAL POINTS: ,;6%s>Cvd(  
5S? "<+J'  
Object space positions are measured with respect to surface 1. !& c%!*  
Image space positions are measured with respect to the image surface. CH+%q+I  
The index in both the object space and image space is considered. zpT{!V  
>kAJS??  
                          Object Space         Image Space ?Ho$fGz  
W = 1.310000 (Primary) x75;-q  
************************************************************ 5%S5*c6BD  
Focal Length          :           -1.639015            1.639015 b5g^{bzwu  
************************************************************ ip'v<%,Q3"  
Focal Planes          :            0.313078           -1.159568 8;=?F>]xn  
Principal Planes      :            1.952094           -2.798584 %/zHL?RqJ  
Anti-Principal Planes :           -1.325937            0.479447 W9cvxsox  
Nodal Planes          :            1.952094           -2.798584 &/
EZn xl  
Anti-Nodal Planes     :           -1.325937            0.479447 3>(~5  
f~d=1
  
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