[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？ n<Z;Xh~F  
一下是我的Prescription Data数据： Hjli)*ev  
GENERAL LENS DATA:
=/J4(#Xb  
!h7`W*::  
Surfaces                :                3 E=w$r  
Stop                    :                1 ?V#%^ 57p  
System Aperture         : Object Space NA = 0.12 m^h"VH,   
Glass Catalogs          : Schott 3S:}fPR  
Ray Aiming              : Paraxial Reference, Cache On B4R!V!Z*  
X Pupil shift          :               0 uJMF\G=nb  
Y Pupil shift          :               0 Kwfrh?  
Z Pupil shift          :               0 ?)1h.K1}M  
Apodization             : Gaussian, factor =   1.00000E+000 %p"x|e  
************************************************************* 8iD_md_[  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) pq*b"Jku1  
Effective Focal Length  :        1.639158 (in image space) \P!v9LX(  
************************************************************* ^o"9f1s5  
Back Focal Length       :       -1.061568 Mq42^m:qe  
Total Track             :           4.318 wCe
Ss=[  
Image Space F/#         :        3.417255 *D F5sY  
Paraxial Working F/#    :        2.950535 N2;T\xx,  
Working F/#             :        2.961912 `8\pihww  
Image Space NA          :       0.1670788 X.xp
'/d  
Object Space NA         :            0.12 TF|GGYi  
Stop Radius             :       0.2398355 SS O$.rp  
Paraxial Image Height   :               0 G=!Y~qg  
Paraxial Magnification  :               0 29u"\f a  
Entrance Pupil Diameter :       0.4796709 DyG3|5s1R  
Entrance Pupil Position :               0 y ']>J+b0  
Exit Pupil Diameter     :        2.511155 > zh%CF$  
Exit Pupil Position     :        7.420935 kJ>l,AD/  
Field Type              : Angle in degrees *f.eyg#  
Maximum Field           :               0 q>r9ooN  
Primary Wave            :            1.31 C>N)~Ut  
Lens Units              :   Millimeters WDY,?  
Angular Magnification   :               0 l+bP48  
nWbe=z&y8[  
Fields          : 1 O\XN/R3  
Field Type: Angle in degrees TuBg4\V  
#        X-Value        Y-Value         Weight :74^?  
1       0.000000       0.000000       1.000000 w@nN3U+  
@8|-
C  
Vignetting Factors 9Q^>.^~^  
#       VDX       VDY       VCX       VCY       VAN -'&MT :L  
1  0.000000  0.000000  0.000000  0.000000  0.000000 bL!NT}y`  
Jm\'
=#U#  
Wavelengths     : 1 f_9%kEXICt  
Units: Microns nmc=RK^cM  
#          Value         Weight Cq u/(=  
1       1.310000       1.000000 rgB`<[:b  
5IBe;o  
CARDINAL POINTS: c3P
 
9X@y*;w<t  
Object space positions are measured with respect to surface 1. <QugV3e  
Image space positions are measured with respect to the image surface. Vg\EAs>f  
The index in both the object space and image space is considered. KZ`d3ad  
eq"a)QB3m  
                          Object Space         Image Space k:Uyez  
W = 1.310000 (Primary) @YU}0&  
************************************************************ 4B<D.i ;}  
Focal Length          :           -1.639015            1.639015 xI<Dc*G  
************************************************************ BGodrb1  
Focal Planes          :            0.313078           -1.159568 4NQS'*%D  
Principal Planes      :            1.952094           -2.798584 X/];*='Q  
Anti-Principal Planes :           -1.325937            0.479447 Up*p*(d3  
Nodal Planes          :            1.952094           -2.798584 I^[R]Js  
Anti-Nodal Planes     :           -1.325937            0.479447 >UE_FC*u  
MH'S,^J  
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