[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？ mbB,j~;^6H  
一下是我的Prescription Data数据：
KY34Sc  
GENERAL LENS DATA: Yv k Qh{  

!Ob  
Surfaces                :                3 =M'M/vKD  
Stop                    :                1 ]Q,;5>#W  
System Aperture         : Object Space NA = 0.12 9pUvw_9MY  
Glass Catalogs          : Schott B!-hcn]y  
Ray Aiming              : Paraxial Reference, Cache On EBlfwFd  
X Pupil shift          :               0 #<0Yx9Jh.  
Y Pupil shift          :               0 (;v)0&h  
Z Pupil shift          :               0 A<P3X/i  
Apodization             : Gaussian, factor =   1.00000E+000 5I/wP qR[  
************************************************************* _OV\W'RrA  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) ^ CVhV  
Effective Focal Length  :        1.639158 (in image space) kR$>G2$!  
************************************************************* D,q=?~  
Back Focal Length       :       -1.061568 jXA!9_L7  
Total Track             :           4.318 !$Aijd s5  
Image Space F/#         :        3.417255 ;,P-2\V/  
Paraxial Working F/#    :        2.950535 DTmv2X  
Working F/#             :        2.961912 WeDeD\zy  
Image Space NA          :       0.1670788 aEU[k>&  
Object Space NA         :            0.12 BCsz
8U!  
Stop Radius             :       0.2398355 ,<?iL~> %  
Paraxial Image Height   :               0 ASmMj;>UM  
Paraxial Magnification  :               0 ,dT.q  
Entrance Pupil Diameter :       0.4796709 = ms(dr^n  
Entrance Pupil Position :               0 <i{O\K]9  
Exit Pupil Diameter     :        2.511155 L[l?}\  
Exit Pupil Position     :        7.420935 6BM[RL?T  
Field Type              : Angle in degrees !OWPwBm;  
Maximum Field           :               0 )
Y%>t  
Primary Wave            :            1.31 Dy6uWv,P  
Lens Units              :   Millimeters (t&]u7Atr  
Angular Magnification   :               0 4w,=6|#  
S\fEV"  
Fields          : 1 HUqG)t*c1  
Field Type: Angle in degrees Td#D\d\R  
#        X-Value        Y-Value         Weight mr:;Wwd  
1       0.000000       0.000000       1.000000 }$M 2XF  
79 zFF  
Vignetting Factors M|!^ #!a(  
#       VDX       VDY       VCX       VCY       VAN H`u8}{7  
1  0.000000  0.000000  0.000000  0.000000  0.000000 +./c=o/v  
dxqVZksg(9  
Wavelengths     : 1 KHwzQ<Z3  
Units: Microns i`[5%6\"&  
#          Value         Weight C!Cg.^;  
1       1.310000       1.000000 jVP70c  
s ^NO(  
CARDINAL POINTS: \b{Aj,6,  
RmS|X"zc  
Object space positions are measured with respect to surface 1. $=dp)  
Image space positions are measured with respect to the image surface. <p@c%e,_  
The index in both the object space and image space is considered. .d< +-w2Mu  
gcYx-gA}  
                          Object Space         Image Space hUirvDvX  
W = 1.310000 (Primary) ;>^oe:@  
************************************************************ wMy$T<:   
Focal Length          :           -1.639015            1.639015 _;
mN1Te  
************************************************************ tX;00g;U.  
Focal Planes          :            0.313078           -1.159568 kP
wgayz  
Principal Planes      :            1.952094           -2.798584 fDc>E+,  
Anti-Principal Planes :           -1.325937            0.479447 _\E{T5  
Nodal Planes          :            1.952094           -2.798584 n}==
 
Anti-Nodal Planes     :           -1.325937            0.479447 w0Q
N5?  
3wXmX  
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