[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？ G@3Jw[t  
一下是我的Prescription Data数据： NY GWA4L  
GENERAL LENS DATA: *=}\cw\A  

<74r  
Surfaces                :                3 OJ1MV7&  
Stop                    :                1 RhWW61!"  
System Aperture         : Object Space NA = 0.12 arc{:u.K  
Glass Catalogs          : Schott m@y<wk(  
Ray Aiming              : Paraxial Reference, Cache On `J$7X  
X Pupil shift          :               0 a0jzt!ci  
Y Pupil shift          :               0 sd _DG8V  
Z Pupil shift          :               0  \62!{  
Apodization             : Gaussian, factor =   1.00000E+000 Hva/C{Y  
************************************************************* "?G?G'yK>  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) P#|}]oG%  
Effective Focal Length  :        1.639158 (in image space)
)&$mFwf  
************************************************************* tH(g;flO)  
Back Focal Length       :       -1.061568 pupt__NZ)n  
Total Track             :           4.318 4iv&!hAc;  
Image Space F/#         :        3.417255 hvc3n> Y[}  
Paraxial Working F/#    :        2.950535 KRM:h`+-.-  
Working F/#             :        2.961912 wzF%R{;  
Image Space NA          :       0.1670788 6@x^,SA  
Object Space NA         :            0.12 R:`)*=rL%  
Stop Radius             :       0.2398355 } 4ZWAzH  
Paraxial Image Height   :               0 z~th{4#E;  
Paraxial Magnification  :               0 `|<? sjY  
Entrance Pupil Diameter :       0.4796709 1pz-jo,2'  
Entrance Pupil Position :               0 & h\!#X0  
Exit Pupil Diameter     :        2.511155 2Z-QVwa*U  
Exit Pupil Position     :        7.420935 ]wUH*\(y  
Field Type              : Angle in degrees iB}*<~`.Eg  
Maximum Field           :               0 }"&Ye  
Primary Wave            :            1.31 T930tX6"h  
Lens Units              :   Millimeters Dqc2;>  
Angular Magnification   :               0 UZ1Au;(|  
6MpV,2:>  
Fields          : 1 0$_WIk  
Field Type: Angle in degrees !ou;yE&<,  
#        X-Value        Y-Value         Weight A
: O"N  
1       0.000000       0.000000       1.000000 w8bvqTQ  
*#1
J  
Vignetting Factors HLCI  
#       VDX       VDY       VCX       VCY       VAN {(l,Uhxl""  
1  0.000000  0.000000  0.000000  0.000000  0.000000 M
vTp%d.  
V0G[f}tm'  
Wavelengths     : 1 8H,k0~D  
Units: Microns ?1**@E0  
#          Value         Weight :m<#\!?  
1       1.310000       1.000000 ,Fn-SrB:  
xkQT#K=i  
CARDINAL POINTS: _:%i6c*"  
p||mR  
Object space positions are measured with respect to surface 1. xX@9wNYD  
Image space positions are measured with respect to the image surface. iqFC~].)  
The index in both the object space and image space is considered. .vie#,la  
WtC&Qyuq  
                          Object Space         Image Space R+El/ya:6  
W = 1.310000 (Primary) i]Bu7Fuu  
************************************************************ 6m@B.+1  
Focal Length          :           -1.639015            1.639015 #8$"84&N.  
************************************************************ 7~SnY\B|  
Focal Planes          :            0.313078           -1.159568 _}cD_$D  
Principal Planes      :            1.952094           -2.798584 fX2OH)6U  
Anti-Principal Planes :           -1.325937            0.479447 $}fY B/  
Nodal Planes          :            1.952094           -2.798584 ltKMvGEF  
Anti-Nodal Planes     :           -1.325937            0.479447 agq4Zy  
0Bk-)z|V  
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