[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？ Y'kD_T`f,  
一下是我的Prescription Data数据： Zk2-U"0\o  
GENERAL LENS DATA: }9e4?7  
>4=sEj  
Surfaces                :                3 Nzz" w_#  
Stop                    :                1 Bsw5A7,-  
System Aperture         : Object Space NA = 0.12 !8ub3oj)  
Glass Catalogs          : Schott M")v ph^  
Ray Aiming              : Paraxial Reference, Cache On 2a2C z'G  
X Pupil shift          :               0 E]6C1C&K  
Y Pupil shift          :               0 *nDyB.(  
Z Pupil shift          :               0 uY5&93R  
Apodization             : Gaussian, factor =   1.00000E+000 Ps0'WRJnx  
************************************************************* |{]\n/M  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) ]t]s/;9]K  
Effective Focal Length  :        1.639158 (in image space) @jg*L2L6  
************************************************************* DGdSu6s$  
Back Focal Length       :       -1.061568 }NDw3{zn  
Total Track             :           4.318 +2`RvQN  
Image Space F/#         :        3.417255 ihKnZcI$i  
Paraxial Working F/#    :        2.950535 hRSRz5 J}  
Working F/#             :        2.961912 j&)+qTV  
Image Space NA          :       0.1670788 "y/GK1C  
Object Space NA         :            0.12 MTBN&4[  
Stop Radius             :       0.2398355 UO8#8  
Paraxial Image Height   :               0 NMmk,  
Paraxial Magnification  :               0 dkJ+*L5  
Entrance Pupil Diameter :       0.4796709 -uN5DJSW  
Entrance Pupil Position :               0 I(ds]E ;_E  
Exit Pupil Diameter     :        2.511155 XX~~SvSM  
Exit Pupil Position     :        7.420935 [2.uwn]i  
Field Type              : Angle in degrees ~:Dr]kt  
Maximum Field           :               0 U$6N-q  
Primary Wave            :            1.31 k61Ot3  
Lens Units              :   Millimeters Ix !O&_6s  
Angular Magnification   :               0 s$J0^8Q~i  
PMjqcdBzm  
Fields          : 1 8vK Z;  
Field Type: Angle in degrees 95>(NwST4  
#        X-Value        Y-Value         Weight )#Ea~>
v  
1       0.000000       0.000000       1.000000 pUZe.S>G  
rC}r99Pe:x  
Vignetting Factors t.c XrX`k  
#       VDX       VDY       VCX       VCY       VAN h djv
/  
1  0.000000  0.000000  0.000000  0.000000  0.000000 Hb=4k)-/]  
*^ncb,1+i  
Wavelengths     : 1 5E?{>1  
Units: Microns X*1vIs;[@  
#          Value         Weight )U e9:e  
1       1.310000       1.000000 B@G'6 ?  
5Y)*-JY1g  
CARDINAL POINTS: K+TRt"W8&s  
`Q^G k{9P  
Object space positions are measured with respect to surface 1. ]wWN~G)2lV  
Image space positions are measured with respect to the image surface. f{AbCi  
The index in both the object space and image space is considered. ^k]OQc7q'  
B<J}YN  
                          Object Space         Image Space su>GeJiPW  
W = 1.310000 (Primary) r
q
Dre`m  
************************************************************ kJq8"Klg  
Focal Length          :           -1.639015            1.639015 y[oc^Zuo
 
************************************************************ /=A^@&:_#  
Focal Planes          :            0.313078           -1.159568 [>Z~&cm  
Principal Planes      :            1.952094           -2.798584 a,x-akZWf  
Anti-Principal Planes :           -1.325937            0.479447 u)y6$  
Nodal Planes          :            1.952094           -2.798584 lNowH0K!D  
Anti-Nodal Planes     :           -1.325937            0.479447 j8WnXp_  
cU?A|'  
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