[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？ <J{'o`{  
一下是我的Prescription Data数据： ra6o>lI(,  
GENERAL LENS DATA: rg QEUDEQ  
hOk00az  
Surfaces                :                3 <4`eQ
 
Stop                    :                1 |qN'P}L  
System Aperture         : Object Space NA = 0.12 eon!CE0  
Glass Catalogs          : Schott *"{&FEV  
Ray Aiming              : Paraxial Reference, Cache On KfY$ka[}"S  
X Pupil shift          :               0 -kj
< 1~YW  
Y Pupil shift          :               0 C"w {\ &R  
Z Pupil shift          :               0 Pz"`MB<'Ik  
Apodization             : Gaussian, factor =   1.00000E+000 t?)pl2!A  
************************************************************* TMVryb  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) @aG&n(.!u*  
Effective Focal Length  :        1.639158 (in image space) xN"Z1n7t  
************************************************************* C+V* Fh3  
Back Focal Length       :       -1.061568 M>H=z#C>/A  
Total Track             :           4.318 E~hzh /,34  
Image Space F/#         :        3.417255 53OJ-m%a  
Paraxial Working F/#    :        2.950535 8E^@yZo{  
Working F/#             :        2.961912 *cv}*D  
Image Space NA          :       0.1670788 *nTU#U  
Object Space NA         :            0.12 \f
Lvw  
Stop Radius             :       0.2398355 Q<"[C 1Lj  
Paraxial Image Height   :               0 ANMg  
Paraxial Magnification  :               0 k#JQxLy#  
Entrance Pupil Diameter :       0.4796709 0ZI(/r  
Entrance Pupil Position :               0  saZ>?Owz  
Exit Pupil Diameter     :        2.511155 2k -+^}r  
Exit Pupil Position     :        7.420935 -X1X)0v$  
Field Type              : Angle in degrees 4? (W%?  
Maximum Field           :               0 z;}6f  
Primary Wave            :            1.31 C;rG]t^%  
Lens Units              :   Millimeters @
R2at  
Angular Magnification   :               0 =(, ^du'  
z3?\:Yz  
Fields          : 1 uG
J"!K  
Field Type: Angle in degrees Iw=Sq8  
#        X-Value        Y-Value         Weight @xWdO,#  
1       0.000000       0.000000       1.000000 hfM;/  
40P) 4
w  
Vignetting Factors n \G Ry'  
#       VDX       VDY       VCX       VCY       VAN WE!vSZ3R  
1  0.000000  0.000000  0.000000  0.000000  0.000000 w!3>N"em  
cPF<D$B  
Wavelengths     : 1 ":W%,`@$  
Units: Microns >yK0iK{  
#          Value         Weight 0~gO'*2P  
1       1.310000       1.000000 `$RA< 3  
{I1~-8  
CARDINAL POINTS: o|8`>!hF  
tpf7_YP_!-  
Object space positions are measured with respect to surface 1. g:)DNy  
Image space positions are measured with respect to the image surface. 1(dj[3Mt  
The index in both the object space and image space is considered. tbDoP Y  
"5|Lz)=  
                          Object Space         Image Space ^HA %q8| n  
W = 1.310000 (Primary) ?pGkk=,KB  
************************************************************ &*,:1=p  
Focal Length          :           -1.639015            1.639015 o4^Fo p  
************************************************************ Ubz"rCjq  
Focal Planes          :            0.313078           -1.159568 OEgI_=B  
Principal Planes      :            1.952094           -2.798584 v> z@  
Anti-Principal Planes :           -1.325937            0.479447 Q=cQLf;/'  
Nodal Planes          :            1.952094           -2.798584 kJK,6mN  
Anti-Nodal Planes     :           -1.325937            0.479447 SAv<&  
JiS5um=(.  
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