[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？ Wk\@n+Q{]  
一下是我的Prescription Data数据： ]M;6o@hq  
GENERAL LENS DATA: `8;,&<U'`  
Reu{   
Surfaces                :                3 \bm6/fhA:  
Stop                    :                1 ttaQlEa=Z  
System Aperture         : Object Space NA = 0.12 kLt9;<L  
Glass Catalogs          : Schott (YHvGGr  
Ray Aiming              : Paraxial Reference, Cache On 
}m%?&c  
X Pupil shift          :               0 =5~F6to  
Y Pupil shift          :               0 -,VhSI  
Z Pupil shift          :               0 S tnv>  
Apodization             : Gaussian, factor =   1.00000E+000 >:E*7
 
************************************************************* oL'1Gm@X?  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) s;2/Nc   
Effective Focal Length  :        1.639158 (in image space) .l+~)$  
************************************************************* ?
[VpN2*  
Back Focal Length       :       -1.061568 @GQ8q]N:<  
Total Track             :           4.318 W Gw!Y1wq  
Image Space F/#         :        3.417255 8A^jD(|  
Paraxial Working F/#    :        2.950535 vM
7vf6  
Working F/#             :        2.961912 ggI=I<7M  
Image Space NA          :       0.1670788 RP,:[}mPl  
Object Space NA         :            0.12 5!F\h'E  
Stop Radius             :       0.2398355 j-YJ."  
Paraxial Image Height   :               0 z5`8G =A  
Paraxial Magnification  :               0 x8?x/xE  
Entrance Pupil Diameter :       0.4796709 Y/,$Y]%g  
Entrance Pupil Position :               0 4su_;+]  
Exit Pupil Diameter     :        2.511155 pEVgJ/>  
Exit Pupil Position     :        7.420935 eKVALUw  
Field Type              : Angle in degrees hiRR+`L%  
Maximum Field           :               0 6f?BltFaN  
Primary Wave            :            1.31 QW~5+c9JJ  
Lens Units              :   Millimeters $iqi:vY  
Angular Magnification   :               0 BKQIo)g.G  
*SkiFEoD  
Fields          : 1 3`k[!!   
Field Type: Angle in degrees rjL?eTU"s  
#        X-Value        Y-Value         Weight f[Fgh@4cj  
1       0.000000       0.000000       1.000000 5U{4TeUH  
sr+gD*@h  
Vignetting Factors _t|G@D{   
#       VDX       VDY       VCX       VCY       VAN jefNiEE[  
1  0.000000  0.000000  0.000000  0.000000  0.000000 gf3U#L}P  
I{
42'9  
Wavelengths     : 1 Er"R;l]xJ  
Units: Microns /z1p/RiX  
#          Value         Weight lC=N:=Mu  
1       1.310000       1.000000 cXS;z.M\_  
Y
 .  
CARDINAL POINTS: 9$o<  
NTm<6Is`  
Object space positions are measured with respect to surface 1. 3+(yI 4  
Image space positions are measured with respect to the image surface. goDV2alC^  
The index in both the object space and image space is considered. .QXG"R  
JFRpsv  
                          Object Space         Image Space hIVI\U,  
W = 1.310000 (Primary) 7-".!M  
************************************************************ LBmM{Gu  
Focal Length          :           -1.639015            1.639015 ;GE26Ymqly  
************************************************************ djsz!$  
Focal Planes          :            0.313078           -1.159568 F1gt3 ae  
Principal Planes      :            1.952094           -2.798584 O`i)?BC  
Anti-Principal Planes :           -1.325937            0.479447 m7r j>X Y  
Nodal Planes          :            1.952094           -2.798584 HKTeqH_:  
Anti-Nodal Planes     :           -1.325937            0.479447 (;0$i?3\  
48tcgFg[  
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