[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？ D ,ZNh1xt  
一下是我的Prescription Data数据： tbzvO<~  
GENERAL LENS DATA: u4#~ i0@  
`?o1cf A  
Surfaces                :                3  mz VuQ  
Stop                    :                1 {.D2ON  
System Aperture         : Object Space NA = 0.12 1xdESorX(  
Glass Catalogs          : Schott ~R?dD
L  
Ray Aiming              : Paraxial Reference, Cache On <,X+
`m&  
X Pupil shift          :               0 ul=a\;3x#|  
Y Pupil shift          :               0 /IJ9_To  
Z Pupil shift          :               0 Z:Y.":[ Qi  
Apodization             : Gaussian, factor =   1.00000E+000 Kpp*^  
************************************************************* ilRm}lU|x  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) KYRm Ui#  
Effective Focal Length  :        1.639158 (in image space) rI^~9Rz  
************************************************************* t2-nCRXEP  
Back Focal Length       :       -1.061568 P$6f+{  
Total Track             :           4.318 &Rl3y\ r  
Image Space F/#         :        3.417255 %AEK[W+0  
Paraxial Working F/#    :        2.950535 ptWG@"j/b  
Working F/#             :        2.961912 \,%o>M'  
Image Space NA          :       0.1670788 gLxT6v5wk.  
Object Space NA         :            0.12 i9@;,4f  
Stop Radius             :       0.2398355 22Y!u00D  
Paraxial Image Height   :               0 gKs/T'PW  
Paraxial Magnification  :               0 sPE)m_u  
Entrance Pupil Diameter :       0.4796709 1^60I#Vr@  
Entrance Pupil Position :               0 ySuLt@X  
Exit Pupil Diameter     :        2.511155 'e<HPNi)  
Exit Pupil Position     :        7.420935 jgo<#AJ/E  
Field Type              : Angle in degrees "
\zj][sL  
Maximum Field           :               0 5<
)gCHa  
Primary Wave            :            1.31 KXx@ {cv  
Lens Units              :   Millimeters CDnR  
Angular Magnification   :               0 pRiH,:\  
{glqWFT  
Fields          : 1 "
doU.U&u  
Field Type: Angle in degrees Pi"~/MGP$  
#        X-Value        Y-Value         Weight
KT lP:pB;  
1       0.000000       0.000000       1.000000 +Jo 3rX'`  
ezg^5o;  
Vignetting Factors ]w_  
#       VDX       VDY       VCX       VCY       VAN i!.I
;@  
1  0.000000  0.000000  0.000000  0.000000  0.000000 E*r
 
\2].|Mym  
Wavelengths     : 1 BDm88<]  
Units: Microns hs{&G^!jo  
#          Value         Weight gI^L 9jE7  
1       1.310000       1.000000 clq~ ;hx  
n?ZL"!$  
CARDINAL POINTS: kyRh k\X  
5D]30
  
Object space positions are measured with respect to surface 1.  d-ag  
Image space positions are measured with respect to the image surface. }DDVGs[  
The index in both the object space and image space is considered. R8=I)I-8  
SLQ\Y%F  
                          Object Space         Image Space Q{.{#G  
W = 1.310000 (Primary) {8!ZKlB  
************************************************************ f!M[awj%  
Focal Length          :           -1.639015            1.639015 +7i7`'9pd  
************************************************************ "}'8`k+d  
Focal Planes          :            0.313078           -1.159568 J8GXI:y  
Principal Planes      :            1.952094           -2.798584 RV0>-@/x  
Anti-Principal Planes :           -1.325937            0.479447 i14[3bPLk!  
Nodal Planes          :            1.952094           -2.798584 9S:
{  
Anti-Nodal Planes     :           -1.325937            0.479447 []A"]p  
 !fQJL   
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