\begin{table}%t2
%\centering
\par
\caption{\label{tableau2}Observing log.}
\begin{tabular}{cccccl}
\hline
\hline
Filter&NOT\# &$\lambda_{\rm c}$&$\Delta\lambda$&System&Exp. time\\
&&(\AA)&(\AA)&&(s)\\
\hline
$V$&75&5300&800&Bessell&3$\;\times\;$1200\\
$i$&12&7970&1570&Gunn&2$\;\times\;$600\\
TiO&--&7780&110&Wing&6$\;\times\;$1200\\
CN&--&8113&85&Wing&6$\;\times\;$1200\\
\hline
\end{tabular}
\end{table}