[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？ &/HoSj>HS  
一下是我的Prescription Data数据： 6ezcS}:+  
GENERAL LENS DATA: #sL
/y  
#uB[&GG}W  
Surfaces                :                3 {d8^@UL  
Stop                    :                1 #&k8TY  
System Aperture         : Object Space NA = 0.12 {K+.A 9!  
Glass Catalogs          : Schott Q<dba12  
Ray Aiming              : Paraxial Reference, Cache On FZeP<Ban  
X Pupil shift          :               0 9wzwY[{  
Y Pupil shift          :               0 ) 9xX  
Z Pupil shift          :               0
%t q&  
Apodization             : Gaussian, factor =   1.00000E+000 @?m+Z"o|z  
************************************************************* C
DJ$hu  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) ^mAJ[^%  
Effective Focal Length  :        1.639158 (in image space) Ln:lC( '  
************************************************************* STw oYn  
Back Focal Length       :       -1.061568 %,XI]+d  
Total Track             :           4.318 L+7*NaPY*  
Image Space F/#         :        3.417255 %U-Qsy8|D)  
Paraxial Working F/#    :        2.950535 >cT
jA):  
Working F/#             :        2.961912 YjX*)Q_sl?  
Image Space NA          :       0.1670788 !f@XDW&R  
Object Space NA         :            0.12 Rw/Ciw2@?  
Stop Radius             :       0.2398355 ::ri3Tu  
Paraxial Image Height   :               0 t]4!{~,  
Paraxial Magnification  :               0 =ydpU<aS  
Entrance Pupil Diameter :       0.4796709 ZH!;z-R  
Entrance Pupil Position :               0 (,shiK[5f  
Exit Pupil Diameter     :        2.511155 %Or2iuO%-,  
Exit Pupil Position     :        7.420935 f P+QxOz  
Field Type              : Angle in degrees FQ1arUOFW,  
Maximum Field           :               0
L(;.n>/  
Primary Wave            :            1.31 \,hrk~4U;(  
Lens Units              :   Millimeters X`D+jiQ(f  
Angular Magnification   :               0 (NPxab8e*  
!KAsvF,j  
Fields          : 1 g(nK$,c  
Field Type: Angle in degrees G#|Hu;C6"  
#        X-Value        Y-Value         Weight RU7!U mf  
1       0.000000       0.000000       1.000000 J,9%%S8/C  
vsc&Ju%k  
Vignetting Factors *N`;I@Q"[  
#       VDX       VDY       VCX       VCY       VAN ~+=E"9O
o  
1  0.000000  0.000000  0.000000  0.000000  0.000000 UP?D@
ogl<  
*{Yh6{  
Wavelengths     : 1 8sH50jeP  
Units: Microns j!7Qw 8  
#          Value         Weight 2Sjt=LOc="  
1       1.310000       1.000000 F'rt>YvF
 
G@B*E%$9  
CARDINAL POINTS: M.S s:ttj  
%Sul4: D#  
Object space positions are measured with respect to surface 1. tq0;^L  
Image space positions are measured with respect to the image surface. lYP~3wp99  
The index in both the object space and image space is considered. g1ytT%]  
QE3ryD  
                          Object Space         Image Space Qne0kB5m  
W = 1.310000 (Primary) JA< :K0  
************************************************************ + LS3T^  
Focal Length          :           -1.639015            1.639015 yZ5x88>  
************************************************************ o_(0  
Focal Planes          :            0.313078           -1.159568 %6Rn4J^^  
Principal Planes      :            1.952094           -2.798584 Fav^^vf*1  
Anti-Principal Planes :           -1.325937            0.479447 z(rK^RT  
Nodal Planes          :            1.952094           -2.798584 >IBTBh_ka  
Anti-Nodal Planes     :           -1.325937            0.479447 F(;jM(  
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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