\begin{table}%t2
\caption{\label{taberr}Uncertainties in the relative photometry from artificial stars experiments, for 10~px~$<$ $r$~$\le$ 160~px, PC~field.}             
\small%\centerline
 {
\begin{tabular}{l c l c}        
\hline\hline                 
{\it F450W} & $\sigma^a$ & {\it F814W} & $\sigma^a$\\    
\hline 
18.00 &  0.009 & 18.00 &   0.010 \\
18.50 &  0.010 & 18.50 &   0.011 \\
19.00 &  0.010 & 19.00 &   0.012 \\
19.50 &  0.011 & 19.50 &   0.013 \\
20.00 &  0.013 & 20.00 &   0.016 \\
20.50 &  0.016 & 20.50 &   0.020 \\
21.00 &  0.018 & 21.00 &   0.026 \\
21.50 &  0.023 & 21.50 &   0.036 \\
22.00 &  0.029 & 22.00 &   0.050 \\
22.50 &  0.039 & 22.50 &   0.068 \\
23.00 &  0.054 & 23.00 &   0.087 \\
23.50 &  0.076 & 23.50 &   0.138 \\
24.00 &  0.107 & 24.00 &   0.218 \\
24.50 &  0.153 & 24.50 &   0.336 \\
25.00 &  0.241 & 25.00 &   0.377 \\
25.50 &  0.309 & 25.50 &   0.400 \\
\hline                                   
\end{tabular}}
\medskip
$^{{a}}$ $\sigma$ are $\pm$1 standard deviations after the clipping of outliers at more than $3\sigma$ from the mean.
\end{table}