[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？ gNQJ:!  
一下是我的Prescription Data数据： Q
jU"|$  
GENERAL LENS DATA: 5xUPqW%3  
K$]B" s  
Surfaces                :                3 H4Ek,m|c  
Stop                    :                1 9Bw"VN]W  
System Aperture         : Object Space NA = 0.12 iL1so+di  
Glass Catalogs          : Schott HI 61rXNF  
Ray Aiming              : Paraxial Reference, Cache On Y|nTc.A  
X Pupil shift          :               0 7SZs/wWh%  
Y Pupil shift          :               0 p~ItHwiT  
Z Pupil shift          :               0 O9)8a]  
Apodization             : Gaussian, factor =   1.00000E+000 $7YLU{0  
************************************************************* 7^=jv~>wP  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) M-|2W~YU  
Effective Focal Length  :        1.639158 (in image space) 1Tr=*b %f  
************************************************************* 'WCTjTob/  
Back Focal Length       :       -1.061568 c= uORt>  
Total Track             :           4.318 vq:j?7  
Image Space F/#         :        3.417255 Z4' v  
Paraxial Working F/#    :        2.950535 7yl'!uz)9  
Working F/#             :        2.961912 pE,BE%
 
Image Space NA          :       0.1670788 < *OF  
Object Space NA         :            0.12 5GkM7Zu!{j  
Stop Radius             :       0.2398355 2Wtfx" .y  
Paraxial Image Height   :               0 Yl])Q|2I  
Paraxial Magnification  :               0 $@;[K\  
Entrance Pupil Diameter :       0.4796709 PQr N";+  
Entrance Pupil Position :               0 -NeF6  
Exit Pupil Diameter     :        2.511155 Q-5wI$=  
Exit Pupil Position     :        7.420935 +%v4Ci"%y  
Field Type              : Angle in degrees K%Bi8d  
Maximum Field           :               0 .*"IJD9  
Primary Wave            :            1.31 \-yi#N  
Lens Units              :   Millimeters W9~datIh>  
Angular Magnification   :               0 yI<'J^1C[  
t:7jlD!d  
Fields          : 1 lc7]=,qyF  
Field Type: Angle in degrees 5H5Kt9DoW  
#        X-Value        Y-Value         Weight &YNhKm@"  
1       0.000000       0.000000       1.000000 6:pN?|=6X  
qcF{Kex"  
Vignetting Factors B#yyO>0k]  
#       VDX       VDY       VCX       VCY       VAN PV2904  
1  0.000000  0.000000  0.000000  0.000000  0.000000 [-ecKPx  
i^l;PvIF  
Wavelengths     : 1 FC#Qtu~J  
Units: Microns l ,.;dw  
#          Value         Weight ."O(Ig[  
1       1.310000       1.000000 oP6G2@3P/  
t {}1f  
CARDINAL POINTS: }s[/b"%y  
[>86i  
Object space positions are measured with respect to surface 1. m/AN*`V  
Image space positions are measured with respect to the image surface. Wwz{98,K  
The index in both the object space and image space is considered. VrK5a9*^  
G'Y|MCKz>  
                          Object Space         Image Space Fz% n!d  
W = 1.310000 (Primary) )LG/n  
************************************************************ X(\RA.64  
Focal Length          :           -1.639015            1.639015 j>iM(8`t1  
************************************************************ q8J/tw?%v  
Focal Planes          :            0.313078           -1.159568 o%a$m9I  
Principal Planes      :            1.952094           -2.798584 `U
R.Rn/x  
Anti-Principal Planes :           -1.325937            0.479447 nj  
Nodal Planes          :            1.952094           -2.798584 D[mYrWHpn  
Anti-Nodal Planes     :           -1.325937            0.479447 J,7\/O(`A  
N.?Wev{  
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