[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？ 8{QN$Qkn  
一下是我的Prescription Data数据： -'ff0l  
GENERAL LENS DATA: '*K}$+l  
iK&s_}i:  
Surfaces                :                3 N,N9K  
Stop                    :                1 mOm_a9ML  
System Aperture         : Object Space NA = 0.12 AG?cI@',  
Glass Catalogs          : Schott h$3o]~t  
Ray Aiming              : Paraxial Reference, Cache On f'501MJu  
X Pupil shift          :               0 };{V]f 0  
Y Pupil shift          :               0
53>y<  
Z Pupil shift          :               0 aPD
4S&"Q  
Apodization             : Gaussian, factor =   1.00000E+000 6@ B_3y  
************************************************************* k0[b4cr`  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) y>4r<YZQ  
Effective Focal Length  :        1.639158 (in image space) `r?xo7  
************************************************************* NrQGoAOw  
Back Focal Length       :       -1.061568 Ll4/P[7:?  
Total Track             :           4.318 "N'|N.,  
Image Space F/#         :        3.417255 BCy# Td  
Paraxial Working F/#    :        2.950535 1>5l(zK!9  
Working F/#             :        2.961912 s.VtmAH  
Image Space NA          :       0.1670788 M.b1=Y  
Object Space NA         :            0.12 ;h|zNx0  
Stop Radius             :       0.2398355 H?\b   
Paraxial Image Height   :               0 A5U//y![{  
Paraxial Magnification  :               0 \q2:1X|  
Entrance Pupil Diameter :       0.4796709 cOz8YVR-  
Entrance Pupil Position :               0 -|Z[GN:  
Exit Pupil Diameter     :        2.511155 )w3?o#@  
Exit Pupil Position     :        7.420935 Y8$Y]2  
Field Type              : Angle in degrees b@6hG
iqx  
Maximum Field           :               0 ,0j7qn@tm  
Primary Wave            :            1.31 _c[Bjip  
Lens Units              :   Millimeters g"c|%3  
Angular Magnification   :               0 xLZJ[:gr  
g7Xjo )  
Fields          : 1 x}\_o< d  
Field Type: Angle in degrees ^tp6G  
#        X-Value        Y-Value         Weight 1#]0\Y(  
1       0.000000       0.000000       1.000000 4gyC?#Ed
e  
suo;+T=`I  
Vignetting Factors tsGt,]O30  
#       VDX       VDY       VCX       VCY       VAN hh%fmc  
1  0.000000  0.000000  0.000000  0.000000  0.000000 {lNvKm)w  
c~,OU7[  
Wavelengths     : 1 }02#[vg  
Units: Microns aHhr_.>X  
#          Value         Weight kfb*|  
1       1.310000       1.000000 no~Yet+<"  
YB;q5[  
CARDINAL POINTS: WR5@S&fU`  
/RWQ+Zf-Y]  
Object space positions are measured with respect to surface 1. 397IbZ\  
Image space positions are measured with respect to the image surface. ,}8|[)"  
The index in both the object space and image space is considered. whoM$  &  
=I(F(AE  
                          Object Space         Image Space 9YMD[H\}V  
W = 1.310000 (Primary) CP5vo-/)-  
************************************************************ \my5E\  
Focal Length          :           -1.639015            1.639015  Rix|LKk{  
************************************************************ Y.7iKMp(  
Focal Planes          :            0.313078           -1.159568 '3<AzR2  
Principal Planes      :            1.952094           -2.798584 M/Twtq-`H  
Anti-Principal Planes :           -1.325937            0.479447 |8m2i1XG  
Nodal Planes          :            1.952094           -2.798584 /Soc,PjZ  
Anti-Nodal Planes     :           -1.325937            0.479447 %1\MW+  
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我用*号，标出了需要注意的地方，请高手指教！

慢慢理解

我也不会先看看再说!~

看的我头晕了,可能是感冒的缘故吧,以后有机会再探讨

等待高手帮忙吧 我也不会!

帮顶！！！！！！！！！！！！！！1

各位指点一下吧，自己顶起来！