[Tex/LaTex] how to set margins in A3 page when using the KOMAoptions command inside an A4 document

geometrykoma-script

I am inserting an A3 page in an A4 document using the KOMAoptions command:

\afterpage{ % Insert after the current page
\clearpage

\KOMAoptions{paper=a3}
\recalctypearea
\begin{figure}[htbp]
    \centering
    \includegraphics[width=1.0\textwidth]{business-schema.png}
    \caption{\texttt{vo business} schema tables}
\end{figure}
\clearpage
\KOMAoptions{paper=A4,pagesize}
\recalctypearea
}

However I'm totally at a loss when trying to change (reduce) the margins on that A3 page. I tried using \newgeometry commands but they changed the size back to A4. Currently the margins I get are too wide, both horizontally and vertically:

enter image description here

Best Answer

By trial and error I've discovered that I can use \addtolength to reduce the margin for the A3 page so as to accommodate a wide graphic set at 1.35 of the textwidth

\afterpage{ % Insert after the current page
\clearpage

\KOMAoptions{paper=a3}
\addtolength{\hoffset}{-2.0cm}
\recalctypearea
\begin{figure}[htbp]
    \centering
    \includegraphics[width=1.35\textwidth]{}
    \caption{\texttt{vo\ business} schema tables}
    \label{fig:vo-business-schema}
\end{figure}

\clearpage
\KOMAoptions{paper=A4,pagesize}
\recalctypearea
}
\restoregeometry