[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？ 8}Pd- .se  
一下是我的Prescription Data数据： sFR'y.  
GENERAL LENS DATA: vt;<+"eps  
"}uPz4  
Surfaces                :                3 PB !\r}Q  
Stop                    :                1 UX-l`ygl  
System Aperture         : Object Space NA = 0.12 \wmNeGC2  
Glass Catalogs          : Schott 97H2hYw9l  
Ray Aiming              : Paraxial Reference, Cache On XxW~4<r  
X Pupil shift          :               0 '/gw`MJ  
Y Pupil shift          :               0 `r; .  
Z Pupil shift          :               0 0:(`t~  
Apodization             : Gaussian, factor =   1.00000E+000 sLx!Do$'  
************************************************************* &} b'cO  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) y{Wtm7fnA  
Effective Focal Length  :        1.639158 (in image space) sje}E+{[  
************************************************************* w!Nt
N4>  
Back Focal Length       :       -1.061568 h[()!\vBy  
Total Track             :           4.318 cmQLkT"#K  
Image Space F/#         :        3.417255 oa:GGW4Q  
Paraxial Working F/#    :        2.950535 c;,jb  
Working F/#             :        2.961912 [CH%(#>i~  
Image Space NA          :       0.1670788 =1o
_:VOG  
Object Space NA         :            0.12 jW6~^>S  
Stop Radius             :       0.2398355 PI7M3\z  
Paraxial Image Height   :               0 {nH. _  
Paraxial Magnification  :               0 Pnb?NVP!^9  
Entrance Pupil Diameter :       0.4796709 f-5vE9G3y7  
Entrance Pupil Position :               0 dQ*3s>B[  
Exit Pupil Diameter     :        2.511155 NpRT\cx3  
Exit Pupil Position     :        7.420935 [YT"UVI  
Field Type              : Angle in degrees F+vgkqs@9  
Maximum Field           :               0 @].Ko[P~  
Primary Wave            :            1.31 tzv&E0|d  
Lens Units              :   Millimeters uS3s  
Angular Magnification   :               0  ]A;zY%>  
N|eus3\E  
Fields          : 1 M*)}F  
Field Type: Angle in degrees zJ42%0g  
#        X-Value        Y-Value         Weight ZHxdrX)  
1       0.000000       0.000000       1.000000 g/+P]c6/  
E Kks8  
Vignetting Factors I:s#,!>  
#       VDX       VDY       VCX       VCY       VAN Bb];qYuCO  
1  0.000000  0.000000  0.000000  0.000000  0.000000 4LYeacL B  
YPAMf&jEF  
Wavelengths     : 1 DSyfF&uC  
Units: Microns P@'<OI  
#          Value         Weight ,R=Mr}@u
 
1       1.310000       1.000000 u\zRWX  
|+//pGx  
CARDINAL POINTS: Oy$*ZG)  
kUAjQ>  
Object space positions are measured with respect to surface 1. x|l[fdm5  
Image space positions are measured with respect to the image surface. 1btQ[a6j  
The index in both the object space and image space is considered. _X{ihf  
//VgPl  
                          Object Space         Image Space =LHE_ AA  
W = 1.310000 (Primary) 8>G3KZ3  
************************************************************ |yiM7U,i  
Focal Length          :           -1.639015            1.639015 EBS04]5ul  
************************************************************ 0_Tr>hz  
Focal Planes          :            0.313078           -1.159568 vX})6O  
Principal Planes      :            1.952094           -2.798584 [QA@XBy6  
Anti-Principal Planes :           -1.325937            0.479447 Hep]jxp+  
Nodal Planes          :            1.952094           -2.798584 m4(
:H(Za  
Anti-Nodal Planes     :           -1.325937            0.479447 Z
^9;sb,x  
']1j Mn  
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