[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？ eX <@qa4<  
一下是我的Prescription Data数据： |TCg`ZS`cZ  
GENERAL LENS DATA: Qi\"b  
l]z=0  
Surfaces                :                3 FlepM*  
Stop                    :                1 "E%3q3|"l  
System Aperture         : Object Space NA = 0.12 _vr;cjMI  
Glass Catalogs          : Schott 7r wNjY#  
Ray Aiming              : Paraxial Reference, Cache On NLF6O9  
X Pupil shift          :               0 Qs;MEt1  
Y Pupil shift          :               0 3Tz~DdB  
Z Pupil shift          :               0 n_
@cjO  
Apodization             : Gaussian, factor =   1.00000E+000 XcM.<Dn3  
************************************************************* Gc{s?rB_  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) HR$;QHl~F  
Effective Focal Length  :        1.639158 (in image space) |oV_7%mlu  
************************************************************* #qg(DgH 7  
Back Focal Length       :       -1.061568 n ?+dX^j  
Total Track             :           4.318 =
JfSg'7  
Image Space F/#         :        3.417255 ?$0t @E  
Paraxial Working F/#    :        2.950535 p _q]Rt  
Working F/#             :        2.961912 (bON[6OGm  
Image Space NA          :       0.1670788 >^zbDU1wT  
Object Space NA         :            0.12 hO0g3^  
Stop Radius             :       0.2398355 X!!3>`|  
Paraxial Image Height   :               0 IhPX/P  
Paraxial Magnification  :               0 )m.U"giG++  
Entrance Pupil Diameter :       0.4796709 ioJr2wq6  
Entrance Pupil Position :               0 zE1=*zO`  
Exit Pupil Diameter     :        2.511155 gkL{]*9&%  
Exit Pupil Position     :        7.420935 ##|]el%Y  
Field Type              : Angle in degrees #Iwxt3K  
Maximum Field           :               0 *W$bhC'w  
Primary Wave            :            1.31 dI) 9@UL  
Lens Units              :   Millimeters jRNDi_u?Wb  
Angular Magnification   :               0 &@/25Y2  
ysFp`  
Fields          : 1 p5JRG2zt  
Field Type: Angle in degrees E% d3}@  
#        X-Value        Y-Value         Weight GLr7sack  
1       0.000000       0.000000       1.000000 T7~Vk2o%(  
D);w)`  
Vignetting Factors m+9~f_}  
#       VDX       VDY       VCX       VCY       VAN C7xmk;c w  
1  0.000000  0.000000  0.000000  0.000000  0.000000 #D|n6[Y'.t  
i4H,Ggb  
Wavelengths     : 1 :C9vs  
Units: Microns <_~e/+_.  
#          Value         Weight j-9Zzgr  
1       1.310000       1.000000 RGy+W-  
xDEjeM G  
CARDINAL POINTS: $#/f+kble  
L{Kl!  
Object space positions are measured with respect to surface 1. B`wrr8"Rz  
Image space positions are measured with respect to the image surface. Y[Eq;a132  
The index in both the object space and image space is considered. YK%rTbB(  
V3c7F4\  
                          Object Space         Image Space 0UOjk.~b  
W = 1.310000 (Primary) dBEm7.nh  
************************************************************ O8)N`#1>+  
Focal Length          :           -1.639015            1.639015 }B@44HdY  
************************************************************ $c}-/U 8  
Focal Planes          :            0.313078           -1.159568 ~NG+DyGa=  
Principal Planes      :            1.952094           -2.798584 y87oW_
"h  
Anti-Principal Planes :           -1.325937            0.479447 OmLe+,7'  
Nodal Planes          :            1.952094           -2.798584 HMq
R%A  
Anti-Nodal Planes     :           -1.325937            0.479447 V2LvE.Kj  
4rrR;V"}  
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