[Tex/LaTex] Setting the beamer titleframe font family to roman

Question

I am creating a beamer presentation, and would like to have my titleframe using the roman font family.

How do we change just one frame?

This may sound trivial to some of you but here is what I tried:

\documentclass[a4paper]{beamer}

\usepackage[utf8]{inputenc} 
\usepackage[T1]{fontenc}
\usepackage[francais]{babel}

% This here doesn't change anything:
\setbeamerfont{frametitle}{family=\rmfamily\selectfont}
\usefonttheme{professionalfonts}

\title{Awesome}
\author{Me \textsc{Myself}}
\date{\today}
\institute{Lab}

\begin{document}
\begin{frame}
\titlepage

\vfill

\begin{center}
Supervision: Dr. Hyde
\end{center}

\end{frame}
\end{document}

Trying to put the frame content in {\rmfamily ...} does not seem the right solution either: I think you cannot put several paragraphs like this in brackets (?).

As a side question, more generally, I often need commands that should be used like this: {\small ...} for example, but an environment would be more appropriate. Isn't there a direct conversion from simple commands (\small, \sffamily, …) to environments?

Answer 1

frametitle has nothing to do with the titlepage, thats what you get as "headline" on slides when you use \frametitle{...}. To modify the font of the titlepage, you have to adjust the components, such as author or date separately.

\documentclass[a4paper]{beamer}

\usepackage[utf8]{inputenc} 
\usepackage[T1]{fontenc}
\usepackage[francais]{babel}

% This here doesn't change anything:
\setbeamerfont{title}{family=\rmfamily\selectfont}
\setbeamerfont{author}{family=\rmfamily\selectfont}
\setbeamerfont{institute}{family=\rmfamily\selectfont}
\setbeamerfont{date}{family=\rmfamily\selectfont}

\usefonttheme{professionalfonts}

\title{Awesome}
\author{Me \textsc{Myself}}
\date{\today}
\institute{Lab}

\begin{document}
\begin{frame}
\titlepage

\vfill

\begin{center}
    \usebeamerfont{author}Supervision: Dr. Hyde
\end{center}

\end{frame}

\frame{normal text}


\end{document}

---

As for the side question, you can probably define your own commands, but please do not complain when (not if) they will break something:

\documentclass{article}

\newcommand{\mysmall}[1]{\begingroup\tiny #1\endgroup}

\begin{document}
normal

\mysmall{small}

normal

\end{document}