[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？ =Jyu4j *}  
一下是我的Prescription Data数据： T7hcn
F$  
GENERAL LENS DATA: ?gt l)q  
xD~5UER  
Surfaces                :                3 8~@c)Z;  
Stop                    :                1 [q8 P~l  
System Aperture         : Object Space NA = 0.12 hYG6 pTCb  
Glass Catalogs          : Schott `T5W}p[6  
Ray Aiming              : Paraxial Reference, Cache On RwpdRBb  
X Pupil shift          :               0 L?mrbay  
Y Pupil shift          :               0 %z,mB$LY  
Z Pupil shift          :               0 CDK5  
Apodization             : Gaussian, factor =   1.00000E+000 l*d(;AR  
************************************************************* ~d|A!S`  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) Nh_Mz;ITuu  
Effective Focal Length  :        1.639158 (in image space) "hH.#5j  
************************************************************* /rnu<Q#iH  
Back Focal Length       :       -1.061568 j i7[nY  
Total Track             :           4.318 V{/?FO?E  
Image Space F/#         :        3.417255 8c9*\S  
Paraxial Working F/#    :        2.950535 4NheWM6  
Working F/#             :        2.961912 kuszb~`zPY  
Image Space NA          :       0.1670788 )<h*eS{  
Object Space NA         :            0.12 3z{?_;bR  
Stop Radius             :       0.2398355 s %j_H  
Paraxial Image Height   :               0 nxnv,AZG  
Paraxial Magnification  :               0 q_A!'sm@)  
Entrance Pupil Diameter :       0.4796709 Z`ID+  
Entrance Pupil Position :               0 / F4z
g3  
Exit Pupil Diameter     :        2.511155 MOQ*]fV:  
Exit Pupil Position     :        7.420935 qNB<T('  
Field Type              : Angle in degrees k@RDvn  
Maximum Field           :               0 $P/~rZ@M@  
Primary Wave            :            1.31 YNKHN2E8  
Lens Units              :   Millimeters }ppN k:B  
Angular Magnification   :               0 1\ o59
Y  
'"0'Oua  
Fields          : 1 Z>:NPZODf  
Field Type: Angle in degrees e>+i>/Fn{h  
#        X-Value        Y-Value         Weight `ZYoA t]C~  
1       0.000000       0.000000       1.000000 s>7}zU]  
gmw|H?]  
Vignetting Factors ]%@M>?Ywc  
#       VDX       VDY       VCX       VCY       VAN S"NqM[W
 
1  0.000000  0.000000  0.000000  0.000000  0.000000 qouhuH_WtJ  
q
kDI](4  
Wavelengths     : 1 GfoLae  
Units: Microns 6F!+T=  
#          Value         Weight `u3E
U*~W  
1       1.310000       1.000000 #rMlI3;  
;=)k<6  
CARDINAL POINTS: Dp,L/1GQ8  
h7G"G"  
Object space positions are measured with respect to surface 1. } gyj0  
Image space positions are measured with respect to the image surface. <wN}X#M  
The index in both the object space and image space is considered. /M1ob:m  
4tRYw0f47  
                          Object Space         Image Space JVvs-bK5
 
W = 1.310000 (Primary) t3 8m'J :>  
************************************************************ X5zDpi|Dq  
Focal Length          :           -1.639015            1.639015 6Z
m# bFQ  
************************************************************ AifWf2$S  
Focal Planes          :            0.313078           -1.159568 yj 3cyLXw  
Principal Planes      :            1.952094           -2.798584 Yb|
c\[ %  
Anti-Principal Planes :           -1.325937            0.479447 ]sf7{lVT  
Nodal Planes          :            1.952094           -2.798584 ?GKb7Oj  
Anti-Nodal Planes     :           -1.325937            0.479447 7Wf/$vRab  
!JHL\M>
A5  
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