\begin{table} %[!ht] %t4
%\centering
\par
\caption{\label{tab4}Accuracy of $A_{V}$,~$R$ determination.}
\vspace*{-2mm}
 \begin{tabular}{lrcrcrclc}  
\hline
\hline\noalign{\smallskip}
        &\multicolumn{5}{l}{PH-method} &\multicolumn{2}{l}
{Photometry\tablefootmark{b}} & \\
Object  & $N$\tablefootmark{a} & $A_{V}$ & $\sigma$$_{A}$ & $R$  & $\sigma$$_{R}$
 & $R$ & quoted & Method \\
        &   & (mag)     & ($\%$)  &   & ($\%$) &  & error ($\%$) & (Sect.~2)\\
\hline 
M~8      & 7  & 2.1 &  11 & 4.35 & 21 & 4.6 & $\pm$6 & 2.1 \\ 
          & 11 & 2.2 &   7 & 6.1  & 11 & 4.6--5.6, 5.3 & & 2.2    \\
M~16     &  9 & 2.8 &   6 & 5.2  & 10 & 4.8 & $\pm$4 & 2.1    \\
M~17     &  7 & 3.5 &   4 & 4.1  & 7  & 4.2--4.9 & $\pm$6--9 & 2.1     \\
          &  9 & 3.05 & 11 & 4.3  & 17 & 4.5 & 5 & 2.2,~ Fig.~\ref{fig5}     \\ 
M~20     & 14 & 1.05 & 20 & 5.5  & 33 & 5.1 &  & 2.2   \\
M~42     &  9 & 2.15 &  9 & 5.8  & 15 & 5.5    & & 2.2    \\
NGC~3603 &  8 & 6.9  &  6 & 5.4  & 10 & 4.3 & $\pm$5 & 2.1    \\ 
S~311    & 10 & 1.9  & 19 & 5.5  & 33 &     & &    \\
NGC~7027 & 7  & 3.9  & 6  & 4.4  &  8 &     & &    \\
\hline
\end{tabular}
\vspace*{-1.5mm}
\tablefoot{
 \tablefoottext{a}{
 Number of lines used in PH-method.}
 \tablefoottext{b}{
  See Table~\ref{tab3} for references.}}
  \end{table}