Caption is bold. Can I have part of it not bold?

Question

What is the simplest way to have part of a bold caption (including some inline math) non-bold?

Answer 1

Put the respective part of the caption in \textmd{}.

\documentclass{article}

\usepackage[font=bf]{caption}

\begin{document}

\begin{figure}
\caption{A bold caption with a \textmd{medium/regular} part}
\end{figure}

\end{document}

EDIT: By default, LaTeX will use (non-bold) italics for inline math even in a bold caption. I assumed that you wanted to change an additional part of the caption to non-bold.