[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？ 'FPcAW^8  
一下是我的Prescription Data数据： `r~`N`o5A  
GENERAL LENS DATA: =9DhO7I'  
Yn I
M-  
Surfaces                :                3 S|{Yvyp  
Stop                    :                1 7GBZA=J  
System Aperture         : Object Space NA = 0.12 nJldz;  
Glass Catalogs          : Schott H7z>S G0  
Ray Aiming              : Paraxial Reference, Cache On YZ"+c&V"  
X Pupil shift          :               0 @b::6n/u  
Y Pupil shift          :               0 a2cx  
Z Pupil shift          :               0 =RW* %8C  
Apodization             : Gaussian, factor =   1.00000E+000 wc6 E-rB  
************************************************************* 7~!I2DV_  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) @MN}^umx`  
Effective Focal Length  :        1.639158 (in image space) 6o[0sM_];  
************************************************************* o ;[C(OS  
Back Focal Length       :       -1.061568 vCy.CN$  
Total Track             :           4.318 \yJZvhUk  
Image Space F/#         :        3.417255 u|_LR5S!j  
Paraxial Working F/#    :        2.950535 dAYI DE  
Working F/#             :        2.961912 ]97Xu_  
Image Space NA          :       0.1670788 %mK3N2N$  
Object Space NA         :            0.12 (ZE%tbm2  
Stop Radius             :       0.2398355 4 o3)*  
Paraxial Image Height   :               0 -vv
 
Paraxial Magnification  :               0 \b_-mnN"  
Entrance Pupil Diameter :       0.4796709 ~&wXXVK3  
Entrance Pupil Position :               0 FSW3'  
Exit Pupil Diameter     :        2.511155 cwH,l$  
Exit Pupil Position     :        7.420935 SBCL1aM  
Field Type              : Angle in degrees (,- 5(fW  
Maximum Field           :               0 R7E]*:0}  
Primary Wave            :            1.31 c0!Te'?  
Lens Units              :   Millimeters F`YFo)W  
Angular Magnification   :               0 >QYh}Z-/%  
RE ![O  
Fields          : 1 3gxf~$)?  
Field Type: Angle in degrees w;N{>)hv  
#        X-Value        Y-Value         Weight Tjd&^m  
1       0.000000       0.000000       1.000000 9>A-$a4R>  
&GXtdO>;Zv  
Vignetting Factors )HJK '@  
#       VDX       VDY       VCX       VCY       VAN EHH|4;P6  
1  0.000000  0.000000  0.000000  0.000000  0.000000 #rhVzN-?)W  
M?E9N{t8)a  
Wavelengths     : 1 [WcS[](ob  
Units: Microns N; rXl8  
#          Value         Weight C#A@)>  
1       1.310000       1.000000 !d:tIu{)  
fswZM\@  
CARDINAL POINTS: yQu vW$  
NJ >I%u*  
Object space positions are measured with respect to surface 1. GYFgEg}  
Image space positions are measured with respect to the image surface. o8w-$ Qb  
The index in both the object space and image space is considered. 1t0bUf;(M  
re7!p(W?,  
                          Object Space         Image Space V[#6yMU@  
W = 1.310000 (Primary) Vil@?Y"  
************************************************************ YH6snC$u  
Focal Length          :           -1.639015            1.639015 5/Ydv RB67  
************************************************************ |!$ Q<-]f  
Focal Planes          :            0.313078           -1.159568 ,)Yao;Cvd  
Principal Planes      :            1.952094           -2.798584 eA`]KalH  
Anti-Principal Planes :           -1.325937            0.479447 ]MC/t5vCu  
Nodal Planes          :            1.952094           -2.798584 V%i<;C  
Anti-Nodal Planes     :           -1.325937            0.479447 \V._Z>]  
-Bl/4p  
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