[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？ U0 nSI  
一下是我的Prescription Data数据： A<fKO <d  
GENERAL LENS DATA: ZVs]_`(+  
^a^b
sKW  
Surfaces                :                3 ^~9fQJNs  
Stop                    :                1 q^; SZ^yW5  
System Aperture         : Object Space NA = 0.12 6<u=hhL  
Glass Catalogs          : Schott v[{g"C  
Ray Aiming              : Paraxial Reference, Cache On dWqKt0uh!  
X Pupil shift          :               0 j)xRzImu  
Y Pupil shift          :               0 rofj&{w  
Z Pupil shift          :               0 I$7|?8  
Apodization             : Gaussian, factor =   1.00000E+000 #s>AiD  
************************************************************* ]Wr2IM  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) R
/ix,GC  
Effective Focal Length  :        1.639158 (in image space) kw{dvE\K  
************************************************************* ~"|MwR!0  
Back Focal Length       :       -1.061568 6 <XQ'tM]N  
Total Track             :           4.318 M15Ce)oB1(  
Image Space F/#         :        3.417255 )O\w'|$G  
Paraxial Working F/#    :        2.950535 "jV:L  
Working F/#             :        2.961912 VRU"2mQ.P6  
Image Space NA          :       0.1670788 S52'!WTq  
Object Space NA         :            0.12 .8e]-^Z  
Stop Radius             :       0.2398355 QOiPDu=8z  
Paraxial Image Height   :               0 {*mf Is  
Paraxial Magnification  :               0 (KxI*  
Entrance Pupil Diameter :       0.4796709 PkX4 !  
Entrance Pupil Position :               0 ;E:vsVK  
Exit Pupil Diameter     :        2.511155 VaP9&tWXj  
Exit Pupil Position     :        7.420935 +q n[F70}  
Field Type              : Angle in degrees !iv6k~.e'2  
Maximum Field           :               0
-[/tS<U  
Primary Wave            :            1.31 C0C2]xx{  
Lens Units              :   Millimeters yX9 .yq  
Angular Magnification   :               0 'F2g2W`  
b3.  
Fields          : 1 6`Hd)T5{w  
Field Type: Angle in degrees =jv3O.zq  
#        X-Value        Y-Value         Weight dynkb901s  
1       0.000000       0.000000       1.000000 |"}oGL6-  
5"sd  
Vignetting Factors `]~1pc  
#       VDX       VDY       VCX       VCY       VAN dCA| )  
1  0.000000  0.000000  0.000000  0.000000  0.000000 Lb]!TOl  
d*$L$1S  
Wavelengths     : 1 5PY4PT=G  
Units: Microns /cHUqn30a  
#          Value         Weight OSoIH`tA  
1       1.310000       1.000000 uA-1VwW+N  
tTEw"DL_-  
CARDINAL POINTS: #`]`gNB0Yg  
ca=sc[ $+  
Object space positions are measured with respect to surface 1. 6v"WI@b4  
Image space positions are measured with respect to the image surface. +Vv+<M  
The index in both the object space and image space is considered. [#@\A]LO  
f/7on|bv
 
                          Object Space         Image Space *kYJwO^  
W = 1.310000 (Primary) srlxp_^  
************************************************************ b:WA}x V  
Focal Length          :           -1.639015            1.639015 'p FK+j  
************************************************************ 2# 72B  
Focal Planes          :            0.313078           -1.159568 .;\uh$c  
Principal Planes      :            1.952094           -2.798584 F(O"S@  
Anti-Principal Planes :           -1.325937            0.479447 bv^wE,+?o  
Nodal Planes          :            1.952094           -2.798584 <-6f}wN  
Anti-Nodal Planes     :           -1.325937            0.479447 $E/N  
m!5MGq~  
我用*号，标出了需要注意的地方，请高手指教！

慢慢理解

我也不会先看看再说!~

看的我头晕了,可能是感冒的缘故吧,以后有机会再探讨

等待高手帮忙吧 我也不会!

帮顶！！！！！！！！！！！！！！1

各位指点一下吧，自己顶起来！