[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？ nZ"{
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一下是我的Prescription Data数据： 6s> sj7  
GENERAL LENS DATA: h<+PP]l=  
=PI^X\if88  
Surfaces                :                3 [8{_i?wY  
Stop                    :                1 Q]yV:7  
System Aperture         : Object Space NA = 0.12 ^qE<yn  
Glass Catalogs          : Schott <)r,CiS  
Ray Aiming              : Paraxial Reference, Cache On Z|V"8jE  
X Pupil shift          :               0 d4b 9rtM  
Y Pupil shift          :               0 V
aOpO8y`  
Z Pupil shift          :               0 d/"gq}NT  
Apodization             : Gaussian, factor =   1.00000E+000 Ry3+
/]  
************************************************************* }qG?Vmq*R[  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) le "JW/BD  
Effective Focal Length  :        1.639158 (in image space) |Ba4 G`
 
************************************************************* Fr1;)WV  
Back Focal Length       :       -1.061568 lCM6T;2ID  
Total Track             :           4.318 |#Yu.c*  
Image Space F/#         :        3.417255 \]tq7  
Paraxial Working F/#    :        2.950535 j<`I\Pmv  
Working F/#             :        2.961912 6n2Vx1b  
Image Space NA          :       0.1670788 ,-w-su=J_  
Object Space NA         :            0.12 K,`).YK  
Stop Radius             :       0.2398355 .=
.yZ  
Paraxial Image Height   :               0 ujI 3tsl  
Paraxial Magnification  :               0 !=8L.^5c  
Entrance Pupil Diameter :       0.4796709 Co
{MIuL  
Entrance Pupil Position :               0 x!Z:K5%O  
Exit Pupil Diameter     :        2.511155 WLg6-@kxXs  
Exit Pupil Position     :        7.420935 q/W{PBb-2k  
Field Type              : Angle in degrees L%c]%3A  
Maximum Field           :               0 ):|G kSm  
Primary Wave            :            1.31 gJ)h9e*m^  
Lens Units              :   Millimeters "1gk-  
Angular Magnification   :               0 d/ 'A\"o+  
0 .6X{kO  
Fields          : 1 3{N p 9y.  
Field Type: Angle in degrees >/*?4  
#        X-Value        Y-Value         Weight sRo<4U0M;l  
1       0.000000       0.000000       1.000000 rw}
5nv  
=]5DYRhX]  
Vignetting Factors rR),~ @]sL  
#       VDX       VDY       VCX       VCY       VAN HJ2]Nz:   
1  0.000000  0.000000  0.000000  0.000000  0.000000 `? 9]'  
"w:\@Jwu(  
Wavelengths     : 1 e)ZyTuj  
Units: Microns =F^->e0N  
#          Value         Weight ~PU1vbv9T  
1       1.310000       1.000000 $ ufSNx(F  
YW4bm  
CARDINAL POINTS: d[P>jl%7  
`JY>v io  
Object space positions are measured with respect to surface 1.  *pS7/Qe  
Image space positions are measured with respect to the image surface. rw=UK`  
The index in both the object space and image space is considered. E7Gi6w~\  
PpJE|[]  
                          Object Space         Image Space Oo3qiw  
W = 1.310000 (Primary) "c!oOaA  
************************************************************ &<fRej]v  
Focal Length          :           -1.639015            1.639015 1 o  
************************************************************ (DELxE  
Focal Planes          :            0.313078           -1.159568 &}L36|A:  
Principal Planes      :            1.952094           -2.798584 R&x7Iq:=D  
Anti-Principal Planes :           -1.325937            0.479447 -Fok%iQ'5  
Nodal Planes          :            1.952094           -2.798584 r0hta)xa  
Anti-Nodal Planes     :           -1.325937            0.479447 j]ln :?\  
1O'*X  
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