Dummy subfigure label without changing anything to the caption formatting

Question

I want to use cleveref to reference to panels inside a figure. Thereby I design the entire figure outside LaTeX with labels a, b, ... for the different panels. To this end I need some dummy subfigures with labels. So what I did was:

\documentclass[prl,twocolumn]{revtex4-2}

\usepackage{subcaption}
\usepackage{graphicx}
\usepackage{cleveref}

\begin{document}
\maketitle

See \cref{fig:1:a}

\begin{figure}
    \begin{subfigure}{\textwidth} % this 'subfigure' env. has no visible content
        \refstepcounter{subfigure}\label{fig:1:a}
        \refstepcounter{subfigure}\label{fig:1:b}
    \end{subfigure}%
    \centering
    \includegraphics[width=.5\textwidth]{example-image}
    \caption{(a) First sub caption. (b) Second sub caption. And some more text}
    \label{fig:1}
\end{figure}

\end{document}

Which gives (zoom):

The problem is however that subcaption changes the formatting of the caption. For completeness, without the subfigure and without including subcaption the caption looked like this (zoom):

Since I do not use the subcaptions for anythings else then a dummy label I do not want to change the formatting of the my caption at all.

So my question is simple: How do I get dummy subcaption labels without the subcaption package?

Answer 1

Option (1) Use \captionsetup[figure]{...} to get back the right format.

    \documentclass[prl,twocolumn]{revtex4-2}

\usepackage{subcaption}
\usepackage{graphicx}
\usepackage{cleveref}

\captionsetup[figure]{textfont=normalfont,singlelinecheck=off,justification=raggedright}% added <<<

\usepackage{kantlipsum}
\begin{document}
    \maketitle
    
    See \cref{fig:1a}
    
    \begin{figure}[ht]
        \begin{subfigure}{\textwidth} % this 'subfigure' env. has no visible content
            \refstepcounter{subfigure}\label{fig:1a}
            \refstepcounter{subfigure}\label{fig:1b}
        \end{subfigure}%
        \centering
        \includegraphics[width=\linewidth]{example-image}% use linewidth <<<
        %\caption{(a) First sub caption. (b) Second sub caption. And some more text}
            \caption{ (\protect\subref{fig:1a}) First sub caption.  (\protect\subref{fig:1b}) Second sub caption. And some more text}
        \label{fig:1}
    \end{figure}

    \kant[1-7]
\end{document}

or (2) Instead of subcaption it can be used subfig. (See the use of \subref{..} in the example)

\documentclass[prl,twocolumn]{revtex4-2}

\usepackage{graphicx}
\usepackage{subfig}
\usepackage{caption}
\usepackage{cleveref}

\usepackage{kantlipsum}

\captionsetup[figure]{textfont=normalfont,singlelinecheck=off,justification=raggedright}

\begin{document}
    \maketitle
    
    See \cref{fig:1a} and  subfigure~\subref{fig:1b}.   
    \begin{figure}[ht!]
        \subfloat{\label{fig:1a}}
        \subfloat{\label{fig:1b}}
        \centering
        \includegraphics[width=\linewidth]{FigureOne.pdf}
        \caption{ \protect\subref{fig:1a} First sub caption.  \protect\subref{fig:1b} Second sub caption. And some more text}
       \label{fig:1}
    \end{figure}
    
    \kant[1-7]
\end{document}

The FigureOne.pdf was generated by this file.

%%file FigureOne.tex

\documentclass[preview, border=5pt]{standalone}
\usepackage{geometry}
\usepackage{subfig}
\usepackage{graphicx}
\begin{document}
    
    \begin{figure}
    \centering
    \subfloat[][]{\includegraphics[width=0.5\textwidth]{example-image-a}}\enspace
    \subfloat[][]{\includegraphics[width=0.5\textwidth]{example-image-b}}
\end{figure}    
\end{document}

Answer 2

Answers (2) by @Simon Dispa suggests using the subfig package. It turns out that it has the option:

\usepackage[caption=false]{subfig}

According to the manual this is what I need:

For compatibility with other packages which modify the caption and where the stan- dard caption package whould interfere with the desired layout, the caption package has a special option, caption=false, which loads the internals (i.e., the "kernel" caption3 package) without modifying the \caption command.

Indeed, in a real example:

\documentclass[prl,twocolumn]{revtex4-2}

\usepackage{graphicx}
\usepackage[caption=false]{subfig}
\usepackage{cleveref}

\usepackage{kantlipsum}

\begin{document}
    \maketitle

    See \cref{fig:1a} and  subfigure~\subref{fig:1b}.
    \begin{figure}[ht!]
        \subfloat{\label{fig:1a}}
        \subfloat{\label{fig:1b}}
        \centering
        \includegraphics[width=\linewidth]{example-image}
        \caption{
            \protect\subref{fig:1a} First sub caption.
            \protect\subref{fig:1b} Second sub caption.
            \kant[8]}
       \label{fig:1}
    \end{figure}

    \kant[1-7]
\end{document}

the results looks like what I would expect:

Indeed, without subfig the formatting is the same: