[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？ ='YR;  
一下是我的Prescription Data数据： c6Wy1d^  
GENERAL LENS DATA: TVYO`9:CW  
U JY`P4(  
Surfaces                :                3 aQkgkV;~  
Stop                    :                1 L{osh0  
System Aperture         : Object Space NA = 0.12 *"4 OXyV  
Glass Catalogs          : Schott $Nnz|y  
Ray Aiming              : Paraxial Reference, Cache On (5VP*
67  
X Pupil shift          :               0 <+C]^*j  
Y Pupil shift          :               0 =XyK/$  
Z Pupil shift          :               0 ]"aC wr  
Apodization             : Gaussian, factor =   1.00000E+000 F@&q4whaVD  
************************************************************* {b} ?I4)  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure)
fXO"Mr1  
Effective Focal Length  :        1.639158 (in image space) X8F _Mb*  
************************************************************* |Q.t]TR'P  
Back Focal Length       :       -1.061568 QD q2<  
Total Track             :           4.318 qH$G_R#)8B  
Image Space F/#         :        3.417255 <(;"L<?D<C  
Paraxial Working F/#    :        2.950535 &QLCij5:  
Working F/#             :        2.961912 [\eUCt F  
Image Space NA          :       0.1670788 $d4eGL2S  
Object Space NA         :            0.12 wbVM'E/&  
Stop Radius             :       0.2398355 NhXTt!S6C  
Paraxial Image Height   :               0 *p p1U>,  
Paraxial Magnification  :               0 |$^,e%bE  
Entrance Pupil Diameter :       0.4796709 r(0I>|u  
Entrance Pupil Position :               0 V_(lZDjh*  
Exit Pupil Diameter     :        2.511155 QV7K~qi  
Exit Pupil Position     :        7.420935 wE;??'O'l  
Field Type              : Angle in degrees [Kx_%Le  
Maximum Field           :               0 8kX3.X`  
Primary Wave            :            1.31 d8/lEmv[  
Lens Units              :   Millimeters !uy?]l  
Angular Magnification   :               0 H>a3\M  
+u:8#!X$RD  
Fields          : 1 >J|I  
Field Type: Angle in degrees rN8 ZQiJC  
#        X-Value        Y-Value         Weight !G Z2|~f9  
1       0.000000       0.000000       1.000000 kfM}j
  
:/K 'P`JaL  
Vignetting Factors fw'$HV76  
#       VDX       VDY       VCX       VCY       VAN q$0^U{j/  
1  0.000000  0.000000  0.000000  0.000000  0.000000 VNx}ADXu]  
v6;XxBR6  
Wavelengths     : 1 :$j!e#?=  
Units: Microns w[UPoG #Uh  
#          Value         Weight {>pB  
1       1.310000       1.000000 ) yRC$7I  
S\MD]>4  
CARDINAL POINTS: rmk'{"  
_T<ney}Y<  
Object space positions are measured with respect to surface 1. M +
~guTh  
Image space positions are measured with respect to the image surface. I^ppEgYSY  
The index in both the object space and image space is considered. yIh>j.P  
\/. Of]YQ  
                          Object Space         Image Space u'<Y#bsR#/  
W = 1.310000 (Primary) 
gU0}.b  
************************************************************ Z#3wMK~  
Focal Length          :           -1.639015            1.639015 #sq-V,8  
************************************************************ k;#$Oxa>t=  
Focal Planes          :            0.313078           -1.159568 RHz'Dz>0  
Principal Planes      :            1.952094           -2.798584 rbqH9 S  
Anti-Principal Planes :           -1.325937            0.479447 (3&@c!E  
Nodal Planes          :            1.952094           -2.798584 '[{M"S  
Anti-Nodal Planes     :           -1.325937            0.479447 6oL-Atf  
;_%61ZI?M<  
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