\begin{table}%t2
%\centering
\par
\caption {rms WFE, image rms width (for the two reference spectral types),
and chromaticity at different field angle locations over the focal plane.
\label{ch_field}}
\begin{tabular}{ccccccc}
\hline
  \hline
   & $X$ position & $Y$ position & rms WFE & Image rms width & Image rms width & Chromaticity \\
   & [degrees]  & [degrees]  & [nm]    &  for a B3V star [mas] & for a M8V star [mas]
   & [${\rm \mu as}$] \\
   \hline
  F1 & 0.53 & 0.00 & 22.03 & 39.27 & 42.85 & 0.00 \\
  F2 & 0.86 & 0.33 & 208.73 & 41.80 & 43.89 & --3071.23 \\
  F3 & 0.86 & --0.33 & 208.73 & 41.81 & 43.89 & 3070.16 \\
  F4 & 0.20 & 0.33 & 39.77 & 41.93 & 44.92 & 2077.02 \\
  F5 & 0.20 & --0.33 & 39.77 & 41.93 & 44.92 & --2077.02 \\
  F6 & 0.70 & 0.17 & 24.32 & 38.51 & 42.54 & 124.94 \\
  F7 & 0.70 & --0.17 & 24.32 & 38.51 & 42.54 & --124.94 \\
  F8 & 0.36 & 0.17 & 28.82 & 40.30 & 43.34 & 2545.20 \\
  F9 & 0.36 & --0.17 & 28.83 & 40.30 & 43.34 & --2545.20 \\
  F10 & 0.86 & 0.00 & 71.09 & 38.95 & 42.76 & 0.00 \\
  F11 & 0.53 & --0.33 & 41.81 & 40.07 & 43.77 & --389.84 \\
  F12 & 0.53 & 0.33 & 41.81 & 40.07 & 43.77 & 389.84 \\
  F13 & 0.20 & 0.00 & 18.59 & 39.28 & 43.02 & 0.00\\
\hline
\end{tabular}
\end{table}