[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？ ~ejHA~QC  
一下是我的Prescription Data数据： E;%{hAD{  
GENERAL LENS DATA: /H\ZCIu/7  
A M# '(k(  
Surfaces                :                3 'A4Lr  
Stop                    :                1 \&SP7~-eq  
System Aperture         : Object Space NA = 0.12 @mW0EJ8bb  
Glass Catalogs          : Schott 2
f4*r
^  
Ray Aiming              : Paraxial Reference, Cache On 'I;pS)sb  
X Pupil shift          :               0 w2 CgEJ%  
Y Pupil shift          :               0 jLZ+HYyG9  
Z Pupil shift          :               0 @T1-0!TM')  
Apodization             : Gaussian, factor =   1.00000E+000 )\t#e`3  
************************************************************* puDy&T  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) iHTxD1D+H  
Effective Focal Length  :        1.639158 (in image space) S0\:1B  
************************************************************* t@b';Cuv  
Back Focal Length       :       -1.061568 )5bhyzSZI  
Total Track             :           4.318 T?Gi;ld7  
Image Space F/#         :        3.417255 |rsu+0Mtz  
Paraxial Working F/#    :        2.950535 ?eeE[F  
Working F/#             :        2.961912 89~)nV)  
Image Space NA          :       0.1670788 cJL>,Z<|%  
Object Space NA         :            0.12 V[CS{H
y'  
Stop Radius             :       0.2398355 *S*;rLH9c  
Paraxial Image Height   :               0 {n{ j*+  
Paraxial Magnification  :               0 m
/CA  
Entrance Pupil Diameter :       0.4796709 cLX~NPD/  
Entrance Pupil Position :               0 =TU"B-*  
Exit Pupil Diameter     :        2.511155 _8t{4C  
Exit Pupil Position     :        7.420935 :*Sl\:_X)  
Field Type              : Angle in degrees 2g|+*.*`  
Maximum Field           :               0 n&k1'KL&  
Primary Wave            :            1.31 5
q@o,d  
Lens Units              :   Millimeters ~u
7a50  
Angular Magnification   :               0 s!uewS.  
1NA>W  
Fields          : 1 =p ^Sn
,t  
Field Type: Angle in degrees 0!\pS{$zB  
#        X-Value        Y-Value         Weight F~z4T/TN%G  
1       0.000000       0.000000       1.000000 b1E>LrL  
k(!#^Mlz[  
Vignetting Factors ga0W;Vq&X  
#       VDX       VDY       VCX       VCY       VAN a'W-&j  
1  0.000000  0.000000  0.000000  0.000000  0.000000 enE8T3   
HP"5*C5D  
Wavelengths     : 1 8+Oyhd*|  
Units: Microns e*=N\$  
#          Value         Weight OlQ7Yi>  
1       1.310000       1.000000 l. !5/\  
LQ373 j-  
CARDINAL POINTS: 67%o83\  
K%Jy?7 U  
Object space positions are measured with respect to surface 1. Q(>89*b&  
Image space positions are measured with respect to the image surface. gtqgf<mS  
The index in both the object space and image space is considered. e\tcP  
44]/rP_m  
                          Object Space         Image Space =X]$J@j  
W = 1.310000 (Primary) yIOoVi\m  
************************************************************ WR%x4\,d#  
Focal Length          :           -1.639015            1.639015 =;`+^  
************************************************************ 9g|o17  
Focal Planes          :            0.313078           -1.159568 !*'uPw:l2  
Principal Planes      :            1.952094           -2.798584 vrLI`3n]  
Anti-Principal Planes :           -1.325937            0.479447 aU4v-9@U8  
Nodal Planes          :            1.952094           -2.798584 rq:R6e  
Anti-Nodal Planes     :           -1.325937            0.479447 1-Sc@WXd  
*&^`Uk,[  
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