[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？ E,X,RM~ +D  
一下是我的Prescription Data数据： VMHY.Rf  
GENERAL LENS DATA: }a`LOBne  
Yv;aQF"a  
Surfaces                :                3 xq{4i|d)  
Stop                    :                1 f]lDJ?+ M  
System Aperture         : Object Space NA = 0.12 u>
E+HxUJ  
Glass Catalogs          : Schott Grqs*V &|g  
Ray Aiming              : Paraxial Reference, Cache On @Q^;qMy  
X Pupil shift          :               0 
pr?/rXw  
Y Pupil shift          :               0 7-LeJRB
 
Z Pupil shift          :               0 Xu$*ZJ5w  
Apodization             : Gaussian, factor =   1.00000E+000 -7`J(f.rYC  
************************************************************* V]AL'}( 0  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) bcZonS  
Effective Focal Length  :        1.639158 (in image space) &qC>*X.  
************************************************************* ,&9|Ac?$  
Back Focal Length       :       -1.061568 N3?d?+A$  
Total Track             :           4.318 +u#x[xO  
Image Space F/#         :        3.417255 o]Ki+ U  
Paraxial Working F/#    :        2.950535 |(V3  
Working F/#             :        2.961912 .jKO 6f  
Image Space NA          :       0.1670788 XVfQscZe  
Object Space NA         :            0.12 fP|\1Y?CS  
Stop Radius             :       0.2398355 IlrmXSr  
Paraxial Image Height   :               0 Dmw,Bi*  
Paraxial Magnification  :               0 x:xQXjJ  
Entrance Pupil Diameter :       0.4796709 3:gk:j#  
Entrance Pupil Position :               0 S]N4o'K}q  
Exit Pupil Diameter     :        2.511155 71%u|k8|  
Exit Pupil Position     :        7.420935 /[s$A?  
Field Type              : Angle in degrees 87Kx7CKF"  
Maximum Field           :               0 GyCpGP|AZ  
Primary Wave            :            1.31 _e'mG'P(  
Lens Units              :   Millimeters 2S;zze7)  
Angular Magnification   :               0 w&{J9'~  
D8ly8]H  
Fields          : 1 +M*a.ra0OF  
Field Type: Angle in degrees g9XtE
  
#        X-Value        Y-Value         Weight D.!4i.)8}  
1       0.000000       0.000000       1.000000 2R!W5gs1<  
`+uXL9
mo  
Vignetting Factors 4Bn+L,}.  
#       VDX       VDY       VCX       VCY       VAN U`Zn*O~/
 
1  0.000000  0.000000  0.000000  0.000000  0.000000 ,&-[$,  
/p>[$`Aq  
Wavelengths     : 1 6D0,ME#  
Units: Microns J0 P  
#          Value         Weight { SfU!  
1       1.310000       1.000000 ;W].j%]Le  
zN1;v6;  
CARDINAL POINTS: \a!<^|C&  
~iWSc8-  
Object space positions are measured with respect to surface 1. Q?@G>uz  
Image space positions are measured with respect to the image surface. 5*AKl< Jl  
The index in both the object space and image space is considered. AMdS+(J  
3(%,2  
                          Object Space         Image Space }>w4!  
W = 1.310000 (Primary) 7r>W r#  
************************************************************ 5IK@<#wE  
Focal Length          :           -1.639015            1.639015 m5Kx}H~  
************************************************************ [7V]=] p  
Focal Planes          :            0.313078           -1.159568 br
Wt  
Principal Planes      :            1.952094           -2.798584 N,|oV|i  
Anti-Principal Planes :           -1.325937            0.479447 gISs+g  
Nodal Planes          :            1.952094           -2.798584 .Dm{mV@*T  
Anti-Nodal Planes     :           -1.325937            0.479447 ]_?y[@ZP  
[_d*J/X  
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