[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？ ZFh+x@  
一下是我的Prescription Data数据： [
\ )Ge  
GENERAL LENS DATA: /i|z.nNO  
fp>.Owt%.  
Surfaces                :                3 |PVt}*0"  
Stop                    :                1 sYbH
|}  
System Aperture         : Object Space NA = 0.12 TJ@Cjy%  
Glass Catalogs          : Schott x<(b|2qf  
Ray Aiming              : Paraxial Reference, Cache On S9sR#  
X Pupil shift          :               0 w2gf&Lc\  
Y Pupil shift          :               0 1'w:`/_  
Z Pupil shift          :               0 n(Y%Vmy  
Apodization             : Gaussian, factor =   1.00000E+000 3HV%4nZLf  
************************************************************* tOdT[&  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) !%L,*'  
Effective Focal Length  :        1.639158 (in image space) LwJ0  
************************************************************* 8|1^|B(l  
Back Focal Length       :       -1.061568 zi]%Zp  
Total Track             :           4.318 .q`{Dgc~  
Image Space F/#         :        3.417255 ;1AG3P'  
Paraxial Working F/#    :        2.950535 CX/(o]  
Working F/#             :        2.961912 D@Da0  
Image Space NA          :       0.1670788 {
i{xo2<1"  
Object Space NA         :            0.12 {kB `>VS  
Stop Radius             :       0.2398355 2i=H"('G)+  
Paraxial Image Height   :               0 3SG?W_  
Paraxial Magnification  :               0 ^y.
UbI  
Entrance Pupil Diameter :       0.4796709 n
n~YK  
Entrance Pupil Position :               0 pJpNO$$w  
Exit Pupil Diameter     :        2.511155 cz
Ww~'."  
Exit Pupil Position     :        7.420935 Iq5pAHm>M6  
Field Type              : Angle in degrees w:=V@-S8  
Maximum Field           :               0 F}?<v8#z0  
Primary Wave            :            1.31 Va<HU:<  
Lens Units              :   Millimeters H-t|i  
Angular Magnification   :               0 hXL|22>w<  
a=}*mF[ug  
Fields          : 1 [IX+M#mf  
Field Type: Angle in degrees z5cYyx r>  
#        X-Value        Y-Value         Weight R'K/t|MC  
1       0.000000       0.000000       1.000000 &V=7D#L  
2OBfHO~D  
Vignetting Factors iDb;_?  
#       VDX       VDY       VCX       VCY       VAN 7_jE[10  
1  0.000000  0.000000  0.000000  0.000000  0.000000 9t:]  
L&2u[ml  
Wavelengths     : 1 $n=lsDnhQ  
Units: Microns 5>0.NiXGf'  
#          Value         Weight %uDG75KP{  
1       1.310000       1.000000 \{|ImCH  
T|4snU2M  
CARDINAL POINTS: Pe7e?79  
dDcZ!rRaL@  
Object space positions are measured with respect to surface 1. 3}Xc71|v  
Image space positions are measured with respect to the image surface. sa-9$},z4  
The index in both the object space and image space is considered. 0%C^8%(x  
t%0?N<9YkU  
                          Object Space         Image Space V^fV7hw<  
W = 1.310000 (Primary) wrv5V M}  
************************************************************ X)Gp7k1w  
Focal Length          :           -1.639015            1.639015 ? 5|/ C  
************************************************************ eD#XDK  
Focal Planes          :            0.313078           -1.159568 _^!vCa7f  
Principal Planes      :            1.952094           -2.798584 $~u.Wq  
Anti-Principal Planes :           -1.325937            0.479447 4iX-(ir,  
Nodal Planes          :            1.952094           -2.798584 dSK0h(8  
Anti-Nodal Planes     :           -1.325937            0.479447 0{rx.C7|  
j~av\SCU*  
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