# Using background image for part of a slide in beamer

Is there a way to set an image as a background for a slide in beamer, but with an overlay specification?

I'm aware of changing the background image for a single slide in Beamer, using something like

{
\usebackgroundtemplate{
\begin{tikzpicture}[remember picture, overlay]
\node[opacity=0.5,inner sep=1pt] at (current page.center)
{\includegraphics[width=\paperwidth,height=\paperheight]{images/example.jpg}};
\end{tikzpicture}}

\begin{frame}{Title}
\begin{itemize}
\item<1-> Item 1
\item<2-> Item 2
\end{itemize}
\end{frame}
}


I would like the background image to appear only when the second item appears. For now, a workaround is to create two slides, have the second \item appear during the second slide, and only set the background of the second slide to the desired image. Is there a way to make this happen without an additional frame?

Just insert the background picture with \item<2-> Item 2 like this:

\begin{frame}{Title}
\begin{itemize}
\item<1-> Item 1
\item<2-> Item 2
\begin{tikzpicture}[remember picture, overlay]
\node[opacity=0.5,inner sep=1pt] at (current page.center)
{\includegraphics[width=\paperwidth,height=\paperheight]{example-image-a}};
\end{tikzpicture}
\end{itemize}
\end{frame}