\begin{table}%t3
\caption{Changes in rms WFE, image rms width, and chromaticity for
the 6 selected cases discussed in Sect. \ref{section5}.\label{sixcases}}
%\centering
\par
\begin{tabular}{cccc}
\hline
  \hline
  Case & rms WFE & Image rms & Chromaticity \\
       &  [nm]   &   width [mas]        &    [mas] \\
   \hline
  1 & 0.00 & 39.26 & 0.000 \\       
  2 & 40.17 & 42.51 & 1.025 \\      
  3 & 33.94 & 41.75 & 1.011 \\      
\par
  4 & 21.50 & 40.14 & 0.000 \\      
  5 & 40.17 & 42.23 & 0.000 \\      
6 & 102.67 & 360.72 & --0.799 \\       
  \hline
\end{tabular}
\end{table}