[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？ vy\RcP  
一下是我的Prescription Data数据： %>g3~yl  
GENERAL LENS DATA: 2fWTY0  
.~l=zu  
Surfaces                :                3 !Ikt '5/  
Stop                    :                1 oz}+T(@O  
System Aperture         : Object Space NA = 0.12 !X;1}  
Glass Catalogs          : Schott :{q<{^c  
Ray Aiming              : Paraxial Reference, Cache On k\NMy#]Zt  
X Pupil shift          :               0 =g|IG [V  
Y Pupil shift          :               0 Ht&:-F+dm  
Z Pupil shift          :               0 4X+ifZO  
Apodization             : Gaussian, factor =   1.00000E+000 O vk_\On  
************************************************************* }x07^4$j  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) V0P>YQq9s  
Effective Focal Length  :        1.639158 (in image space) 4\4FolsK  
************************************************************* Cd>WUw  
Back Focal Length       :       -1.061568 p(/dBt[3k  
Total Track             :           4.318 #0y)U;dA+w  
Image Space F/#         :        3.417255 PqiB\~o@Z  
Paraxial Working F/#    :        2.950535 f7X6fr<  
Working F/#             :        2.961912 qa0 yg8,<  
Image Space NA          :       0.1670788 g.zEn/SM  
Object Space NA         :            0.12 ^$'z!+QRM  
Stop Radius             :       0.2398355 CTZh0x  
Paraxial Image Height   :               0  y"H*%]  
Paraxial Magnification  :               0 <U!`J[n%  
Entrance Pupil Diameter :       0.4796709 ^HqY9QT2  
Entrance Pupil Position :               0 |
4uWh  
Exit Pupil Diameter     :        2.511155 xT+
zU}z  
Exit Pupil Position     :        7.420935 X ><?F|#7T  
Field Type              : Angle in degrees rjp-Fw~1w  
Maximum Field           :               0 3v5%y'  
Primary Wave            :            1.31 3< 2}V  
Lens Units              :   Millimeters '8{Ne!y  
Angular Magnification   :               0 ^]W<X"H+Z  
 D0%Ug>  
Fields          : 1 b-{=s+:  
Field Type: Angle in degrees k6sI L3QJ0  
#        X-Value        Y-Value         Weight :n.f_v}6  
1       0.000000       0.000000       1.000000 ?MgUY)X  
a{qM2P(S  
Vignetting Factors T`;%TO*Y  
#       VDX       VDY       VCX       VCY       VAN OeS\7  
1  0.000000  0.000000  0.000000  0.000000  0.000000 '~&9D:(  
LYaZ1*  
Wavelengths     : 1 7]||UuF<  
Units: Microns &iA?+kV  
#          Value         Weight 2IKnhBSV3  
1       1.310000       1.000000 DW_1,:,?7l  
dVi!Q@y+  
CARDINAL POINTS: ~=
=>pj  
S=e{MI  
Object space positions are measured with respect to surface 1. q(.:9A*0  
Image space positions are measured with respect to the image surface. "F.;Dv9V[0  
The index in both the object space and image space is considered. Z`KC%!8K  
-/g B|J  
                          Object Space         Image Space 3P^sM1  
W = 1.310000 (Primary) oIb|*gX^  
************************************************************ b/{t|io{  
Focal Length          :           -1.639015            1.639015 ^ml'?  
************************************************************ o8-^cP1  
Focal Planes          :            0.313078           -1.159568 Z^IPZF  
Principal Planes      :            1.952094           -2.798584 :=\Hoz  
Anti-Principal Planes :           -1.325937            0.479447 Te}8!_ohyC  
Nodal Planes          :            1.952094           -2.798584 Htgx`N|  
Anti-Nodal Planes     :           -1.325937            0.479447 w &(|e <  
}7 c[Q($K  
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