CASSEGHAIN REFLECTOR WITH CORRECTED FIELD. 



M = T5200. 

 Aberration Coefficients at F' 7 . 



50 



= -'00058 



SM = +'91421 



S a R = +333-62567 



. (36) 



From these results we read the particulars of the field from the data given on 

 p. 30. We have, by pp. 58, 49, 



/' = +5'088015, a =+'200000. 



Hence, from <S,G, we find for the remaining spherical aberration a circle of radius 

 0""0004 at distance '000001 before the axial focus. 



I 2 



