[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？ &`fhEN  
一下是我的Prescription Data数据： #Jna6  
GENERAL LENS DATA: H<QT3RF2  
l/Vo-#  
Surfaces                :                3 a&k_=/X&  
Stop                    :                1 AQc,>{Lm  
System Aperture         : Object Space NA = 0.12 1Jj Y!  
Glass Catalogs          : Schott J!5v~<v?-  
Ray Aiming              : Paraxial Reference, Cache On 5l,ZoB
8  
X Pupil shift          :               0 tw(JZDc  
Y Pupil shift          :               0 NNF>Xa`9,  
Z Pupil shift          :               0 doB  
Apodization             : Gaussian, factor =   1.00000E+000 meCC?YAB  
************************************************************* Q//,4>JKf  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) 3 E3qd'  
Effective Focal Length  :        1.639158 (in image space) YOrrkbJ(  
************************************************************* @?[1_g_'P  
Back Focal Length       :       -1.061568 7Su#Je]  
Total Track             :           4.318 Ed:eGm }  
Image Space F/#         :        3.417255 R@wjccu  
Paraxial Working F/#    :        2.950535 2QNNp:`6  
Working F/#             :        2.961912 F|&{Rt  
Image Space NA          :       0.1670788 @&"Pci+-|  
Object Space NA         :            0.12 'oN\hy($,h  
Stop Radius             :       0.2398355 !gLk
J)  
Paraxial Image Height   :               0 DaH?@Q
 
Paraxial Magnification  :               0 NWd<+-pC6  
Entrance Pupil Diameter :       0.4796709
XUF\r]B,9  
Entrance Pupil Position :               0 0[F:'_  
Exit Pupil Diameter     :        2.511155 @A+RVg*=  
Exit Pupil Position     :        7.420935 KE1ao9H8wR  
Field Type              : Angle in degrees } %'bullT  
Maximum Field           :               0 )I\=BPo|B  
Primary Wave            :            1.31 vm'5s]kdh
 
Lens Units              :   Millimeters =0- $W5E  
Angular Magnification   :               0 i%{3W:!4t  
0A:n0[V:]  
Fields          : 1 s!9dQ.  
Field Type: Angle in degrees WO6/X/#8b  
#        X-Value        Y-Value         Weight Q`#4W3-,  
1       0.000000       0.000000       1.000000 \j2;4O?`  
uHIiH@S  
Vignetting Factors Jjl%R[mI  
#       VDX       VDY       VCX       VCY       VAN zyg:nKQW  
1  0.000000  0.000000  0.000000  0.000000  0.000000 {ls+dx/  
}P3tn  
Wavelengths     : 1 c>1RP
5vx  
Units: Microns `funE:>,  
#          Value         Weight +f0~D(d!_  
1       1.310000       1.000000 D{v8q)5r  
Gd+ET  
CARDINAL POINTS: f1PN|  
"C?5f]T  
Object space positions are measured with respect to surface 1. \7z^!m  
Image space positions are measured with respect to the image surface. .d?%;2*{q  
The index in both the object space and image space is considered. _al|'obomy  
ICB~_O5  
                          Object Space         Image Space 0GDvwy D1  
W = 1.310000 (Primary) 0Y
]0!}  
************************************************************ L&-hXGx=7  
Focal Length          :           -1.639015            1.639015 y[@\j9Hq  
************************************************************ ^+SkCO  
Focal Planes          :            0.313078           -1.159568 #,(sAj  
Principal Planes      :            1.952094           -2.798584 fnCItK~y  
Anti-Principal Planes :           -1.325937            0.479447 O9(r{Vu7u  
Nodal Planes          :            1.952094           -2.798584 as+GbstN  
Anti-Nodal Planes     :           -1.325937            0.479447 zNSu  
K1?Gmue#I  
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