[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？ %bhFl,tL  
一下是我的Prescription Data数据： w< |Lx#L}  
GENERAL LENS DATA: V##TG0  
8w3Wy<}y  
Surfaces                :                3 2u}ns8wn  
Stop                    :                1 9kas]zQ%=P  
System Aperture         : Object Space NA = 0.12 GS!1K(7  
Glass Catalogs          : Schott 35SL*zS@-
 
Ray Aiming              : Paraxial Reference, Cache On 3,@|kN<  
X Pupil shift          :               0 =ZARJ40L  
Y Pupil shift          :               0 }An;)!>(nF  
Z Pupil shift          :               0 h)?Km{u%  
Apodization             : Gaussian, factor =   1.00000E+000 '/F~vSQsR  
************************************************************* *18J$  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) )B Xl|V,  
Effective Focal Length  :        1.639158 (in image space) 
I8:G:s:  
************************************************************* 4"V6k4i5  
Back Focal Length       :       -1.061568 3;EBKGg|  
Total Track             :           4.318 +|spC  
Image Space F/#         :        3.417255 l,E4h-$  
Paraxial Working F/#    :        2.950535 <Ow+LJWQK  
Working F/#             :        2.961912 NJ!}(=1|K  
Image Space NA          :       0.1670788 o){<PN|z  
Object Space NA         :            0.12 toC|vn&P  
Stop Radius             :       0.2398355 g_MxG!+(V  
Paraxial Image Height   :               0  ev(E  
Paraxial Magnification  :               0 H~ =;yy  
Entrance Pupil Diameter :       0.4796709 wW'.bqA  
Entrance Pupil Position :               0 izr 3{y5  
Exit Pupil Diameter     :        2.511155 uulzJb
V,K  
Exit Pupil Position     :        7.420935 L(kW]  
Field Type              : Angle in degrees Z4PAdT  
Maximum Field           :               0 %lN4"jtx  
Primary Wave            :            1.31 !Ka~X!+\  
Lens Units              :   Millimeters KKJa?e`C  
Angular Magnification   :               0 \1#!%I=.  
78u=Jz6  
Fields          : 1 c}#(,<8X  
Field Type: Angle in degrees =D?{d{JT  
#        X-Value        Y-Value         Weight V?z
-Dt C  
1       0.000000       0.000000       1.000000 HAMps[D[  
H?dEgubg7]  
Vignetting Factors qyYf&VC}  
#       VDX       VDY       VCX       VCY       VAN 1s#GY<<  
1  0.000000  0.000000  0.000000  0.000000  0.000000 `k'Dm:*`u4  
8HH\wu$$e  
Wavelengths     : 1 W:=CpbwENX  
Units: Microns K|{&SU_m  
#          Value         Weight e\i}@]  
1       1.310000       1.000000 ZZF\;  
#'h(o/hz&&  
CARDINAL POINTS: =zKbvwe%X  
ZUeA&&{  
Object space positions are measured with respect to surface 1. >U')ICD~  
Image space positions are measured with respect to the image surface. 3x~AaC.j  
The index in both the object space and image space is considered. kpO+  
^]?Yd)v  
                          Object Space         Image Space 05vu{>  
W = 1.310000 (Primary) m?Dk(DJ  
************************************************************ |0aGX]Y  
Focal Length          :           -1.639015            1.639015 Qx !! Ttd{  
************************************************************ V
@1K  
Focal Planes          :            0.313078           -1.159568 Zl`sY5{1  
Principal Planes      :            1.952094           -2.798584 JB\BP$ap  
Anti-Principal Planes :           -1.325937            0.479447 3`\)Qm  
Nodal Planes          :            1.952094           -2.798584 .(8eWc YK  
Anti-Nodal Planes     :           -1.325937            0.479447 vD4<G{  
v_ W03\  
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