\begin{table}%t1
\caption{Values of the rms intensity contrast after applying the PSFs
  corresponding to the MTFs shown in Fig.~\ref{fig:mtfs}.}
\label{tab:rms}
%\centering
\small
\begin{tabular}{l c}
\hline \hline
Effects taken into account & rms [\%] \\
\hline
none & 14.4 \\
Airy & 10.9 \\
+ central obscuration & 9.6 \\
+ spider & 8.7 \\
+ CCD & 8.5 \\
+ defocus (1.5 mm) & 7.5 \\
\hline
\end{tabular}
\end{table}