如何分析Ghost focus generator的结果

Ghost Trace Data ,JfP$HJ  
File : C:\Program Files\ZEMAX - Beta\Samples\Sequential\Objectives\Cooke 40 degree field.zmx yYdh+x  
Title: A SIMPLE COOKE TRIPLET. #X2wy$GTG  
Units are Millimeters. 8\p"V.o>  
Wavelength: 0.550000 μm rA}mp]
 
Type: Double Bounces JA4}Bwn  
The '****' denotes a possible internal focus dF*M"|
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RMS is the RMS spot radius on axis at the primary wavelength. 9U Hh#  
RMS values of 0.00 indicate that an accurate RMS eo^C[# .  
could not be computed, usually due to ray errors. C9*[/|T  
This analysis may be inaccurate if the system is i!iG7X)qT  
non-rotationally symmetric or uses non-standard surfaces. j{6O:d6([$  
Ghost reflection off surface 2 then 1. (GH002001.ZMX) M5 ^qc  
Surf     Marginal          F/#          RMS c
Un>gT  
   1  5.0000E+000     5.737068  3.5355E+000 +'_ peT.8  
   2  4.7160E+000     4.595701  3.3570E+000 *E+VcU  
   1  4.3614E+000     0.990012  3.1277E+000 8+H 0  
   2  2.7155E+000     0.607262  1.9876E+000 1C0' Gf)3  
   3 -2.2309E+000     0.916280  2.6065E+000 wQa,ol_p  
   4 -2.7766E+000     0.514753  0.0000E+000 rU|?3x  
   5 -7.3909E+000     0.888038  0.0000E+000 L nyow}  
   6 -9.0530E+000     0.823473  0.0000E+000 O^@F?CG :1  
   7 -3.4681E+001     0.823473  0.0000E+000 NDJP`FI  
Marginal ray height    :       -34.6809 ^ 4*#QtO  
Chief ray height       :       -24.8107 |XV`A)=f  
Distance to ghost pupil:       -50.9613 t<"%m)J  
Distance to ghost focus:       -57.1176 I@TH^8(  
Effective focal length :         8.2347