Using background image for part of a slide in beamer

Question

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?

Answer 1

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}