[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？ ktRGl>J  
一下是我的Prescription Data数据： a]Y9;(  
GENERAL LENS DATA: 2kk; z0f  
o?cNH  
Surfaces                :                3 o\PHs4Ws'7  
Stop                    :                1 rg=Ym.  
System Aperture         : Object Space NA = 0.12 F@#p  
Glass Catalogs          : Schott ;.rY`<|  
Ray Aiming              : Paraxial Reference, Cache On ]>ndFE6kl  
X Pupil shift          :               0 :."6g)T  
Y Pupil shift          :               0 %mD{rG9  
Z Pupil shift          :               0 5iI(A'R[7  
Apodization             : Gaussian, factor =   1.00000E+000 "c?31$6  
************************************************************* E$&bl  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) 7TU xdI  
Effective Focal Length  :        1.639158 (in image space) /1D.Ud^  
************************************************************* V#+F*w?&D  
Back Focal Length       :       -1.061568 US"UkY-\  
Total Track             :           4.318 \zwm:@lG  
Image Space F/#         :        3.417255 _ysakn  
Paraxial Working F/#    :        2.950535 g$vOWSI+  
Working F/#             :        2.961912 \rO!lvX  
Image Space NA          :       0.1670788 ori[[~OyB  
Object Space NA         :            0.12 P2 qC[1hYH  
Stop Radius             :       0.2398355 XX "3.zW  
Paraxial Image Height   :               0 $ER9u2  
Paraxial Magnification  :               0 eAqpP>9n  
Entrance Pupil Diameter :       0.4796709 }W(t>>  
Entrance Pupil Position :               0 O(9*
VoD  
Exit Pupil Diameter     :        2.511155 @?;)x&<8?3  
Exit Pupil Position     :        7.420935 [d-Y1  
Field Type              : Angle in degrees :XoR~syT  
Maximum Field           :               0 vlipB}  
Primary Wave            :            1.31 tA,J~|+f:  
Lens Units              :   Millimeters *~*"p)`<  
Angular Magnification   :               0 U[OUIXUi  
Y7 K2@257  
Fields          : 1 \PFjw9s  
Field Type: Angle in degrees pp{GaCi  
#        X-Value        Y-Value         Weight J, +/<Y!  
1       0.000000       0.000000       1.000000 QUfF>,[sv  

0I do_V  
Vignetting Factors J83C]2~7  
#       VDX       VDY       VCX       VCY       VAN `*`ZgTV  
1  0.000000  0.000000  0.000000  0.000000  0.000000 {*r!oD!'  
)K`tnb.Pf  
Wavelengths     : 1 AxF$7J(  
Units: Microns rusYNb1J  
#          Value         Weight QFoCi&  
1       1.310000       1.000000 L/%{,7l<^?  
Fg}t{e]3a  
CARDINAL POINTS: T&bB8tQk  
tp }Bz&V  
Object space positions are measured with respect to surface 1. Bn=YGEvz  
Image space positions are measured with respect to the image surface. ~V?\@R:g  
The index in both the object space and image space is considered. w>}n1Nc$G  
\OWxf[  
                          Object Space         Image Space _JA)""l%  
W = 1.310000 (Primary) =<zlg~i  
************************************************************ %da-/[  
Focal Length          :           -1.639015            1.639015 Y?zo")  
************************************************************ [Ls%nz|  
Focal Planes          :            0.313078           -1.159568 8<KC-|y.  
Principal Planes      :            1.952094           -2.798584 Z:V<P,N  
Anti-Principal Planes :           -1.325937            0.479447 /11CC \  
Nodal Planes          :            1.952094           -2.798584 ^P A|RFP  
Anti-Nodal Planes     :           -1.325937            0.479447 {a9.0N:4  
Tu,nX'q]m  
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