[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？
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一下是我的Prescription Data数据： 2o0WS~}5  
GENERAL LENS DATA: c>#3{}X|x%  
*o=( w5   
Surfaces                :                3 h<BTu7a`r  
Stop                    :                1
mxCqN1:#  
System Aperture         : Object Space NA = 0.12 d ?,wEfwp  
Glass Catalogs          : Schott =%;TVJk*a  
Ray Aiming              : Paraxial Reference, Cache On Q+E)_5_sA  
X Pupil shift          :               0 Acb %)Y  
Y Pupil shift          :               0 @8SA^u0  
Z Pupil shift          :               0 08nA}+k  
Apodization             : Gaussian, factor =   1.00000E+000 Z%VgAV>>  
************************************************************* NcIr; }  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) 
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Effective Focal Length  :        1.639158 (in image space) W!a'KI'  
************************************************************* |eej}G(,m}  
Back Focal Length       :       -1.061568 j<A;
i  
Total Track             :           4.318 bX+"G}CRP  
Image Space F/#         :        3.417255 :2;c@ uj  
Paraxial Working F/#    :        2.950535 Kr%O}<"  
Working F/#             :        2.961912 ^=w){]G  
Image Space NA          :       0.1670788 ->@iw!5xu  
Object Space NA         :            0.12 ^ }|$_  
Stop Radius             :       0.2398355 rmhL|! Y  
Paraxial Image Height   :               0 E,|OMK#   
Paraxial Magnification  :               0 )oMMDHw\  
Entrance Pupil Diameter :       0.4796709 VCUsvhI  
Entrance Pupil Position :               0 q>VvXUyK,  
Exit Pupil Diameter     :        2.511155 >NBwtF>  
Exit Pupil Position     :        7.420935 zUJPINDb  
Field Type              : Angle in degrees ->&amPv
 
Maximum Field           :               0 C33=<r[;N<  
Primary Wave            :            1.31 DA/\[w?J  
Lens Units              :   Millimeters Kd3EZo.  
Angular Magnification   :               0 p+:MZP -%(  
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Fields          : 1 !JPZ7_nn  
Field Type: Angle in degrees g|x*sZR~Y  
#        X-Value        Y-Value         Weight VOrBN
u  
1       0.000000       0.000000       1.000000 OH vV_  
h%U,g 9_  
Vignetting Factors e|.a%,Dcy  
#       VDX       VDY       VCX       VCY       VAN zR }vw{  
1  0.000000  0.000000  0.000000  0.000000  0.000000 /Au7X'}  

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Wavelengths     : 1 `FIS2sl/  
Units: Microns V(6Ql j7  
#          Value         Weight #h2 qrX&+  
1       1.310000       1.000000 F3<Ip~K  
e `IL7$  
CARDINAL POINTS: lC=T{rR  
Zex`n:Wl?j  
Object space positions are measured with respect to surface 1. 8|IlJiJ~v  
Image space positions are measured with respect to the image surface. 6Vy4]jdT5  
The index in both the object space and image space is considered. +(##B pC  
 =E:a\r  
                          Object Space         Image Space 3aEO9v,n  
W = 1.310000 (Primary) a O(&<  
************************************************************ h2ou]  
Focal Length          :           -1.639015            1.639015 )|L#i2?:  
************************************************************ Yq-7!  
Focal Planes          :            0.313078           -1.159568 MF4B 2d  
Principal Planes      :            1.952094           -2.798584 BPC>  
Anti-Principal Planes :           -1.325937            0.479447 $Q*^c"&  
Nodal Planes          :            1.952094           -2.798584 _SQ0`=+  
Anti-Nodal Planes     :           -1.325937            0.479447 LKu ,H  
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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