[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？ e1`)3-f  
一下是我的Prescription Data数据： Ng."+&  
GENERAL LENS DATA: +2V%'{:  
1(:b{Bl  
Surfaces                :                3 M=\d_O#;Z  
Stop                    :                1 9!O+Ryy?\  
System Aperture         : Object Space NA = 0.12 o}mhy`}  
Glass Catalogs          : Schott kol,Qs  
Ray Aiming              : Paraxial Reference, Cache On kKxL04  
X Pupil shift          :               0 VRd:2uDS  
Y Pupil shift          :               0 C NzSBm  
Z Pupil shift          :               0 *%Nns',  
Apodization             : Gaussian, factor =   1.00000E+000 5&n988gC8  
************************************************************* AF*ni~  
Effective Focal Length  :        1.639158 (in air at system temperature and pressure) GFQG(7G9  
Effective Focal Length  :        1.639158 (in image space) 4[5lX C  
************************************************************* A{i][1N  
Back Focal Length       :       -1.061568 nj~$%vmA  
Total Track             :           4.318 iJCY /*C}  
Image Space F/#         :        3.417255 q*F~~J!P  
Paraxial Working F/#    :        2.950535 Ypn%[sSOp  
Working F/#             :        2.961912 I*+LJy;j
 
Image Space NA          :       0.1670788 H#kAm!H
 
Object Space NA         :            0.12 GG@I!2,_  
Stop Radius             :       0.2398355 D y`W5_xSz  
Paraxial Image Height   :               0 c]%;^)  
Paraxial Magnification  :               0 oN&rq6eN  
Entrance Pupil Diameter :       0.4796709 Y'<uZl^aX  
Entrance Pupil Position :               0 _ bXVg3oDt  
Exit Pupil Diameter     :        2.511155 E !Oz|q  
Exit Pupil Position     :        7.420935 #|{BGVp  
Field Type              : Angle in degrees &#vk4C_8m  
Maximum Field           :               0 3ZW/$KP/  
Primary Wave            :            1.31 'uP'P#  
Lens Units              :   Millimeters Ad}-I%Ie  
Angular Magnification   :               0 `zElB
D  
{dy` %It  
Fields          : 1 "%.|n|  
Field Type: Angle in degrees fB;&n  
#        X-Value        Y-Value         Weight d{iu+=NXz  
1       0.000000       0.000000       1.000000 f"ZqA'KB#  
R\9>2*w  
Vignetting Factors CU#L *kz  
#       VDX       VDY       VCX       VCY       VAN ~4
MtDf  
1  0.000000  0.000000  0.000000  0.000000  0.000000 (B>yaM#5  
$n=W2WJ6f  
Wavelengths     : 1 V
r&el  
Units: Microns h"Vp
Qhi  
#          Value         Weight T=eT^?v  
1       1.310000       1.000000 S 0R8'Y  
mC*W2#1pF  
CARDINAL POINTS: %K&+~CJE  
7.7Cluh5,  
Object space positions are measured with respect to surface 1. SE-!|WR  
Image space positions are measured with respect to the image surface. V9+xL 1U#  
The index in both the object space and image space is considered. } D/+<  
yM(_P0  
                          Object Space         Image Space ;x!,g5q"q  
W = 1.310000 (Primary) l1-4n*fU  
************************************************************ Ap F*a$),  
Focal Length          :           -1.639015            1.639015
O tXw/  
************************************************************ im_w+h%^  
Focal Planes          :            0.313078           -1.159568 '+)6#/*  
Principal Planes      :            1.952094           -2.798584 NDB*BmG  
Anti-Principal Planes :           -1.325937            0.479447 ,X9hl J  
Nodal Planes          :            1.952094           -2.798584 _/8_,9H  
Anti-Nodal Planes     :           -1.325937            0.479447 g2[K<  
XsAY4WT
S  
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