How do I reference photographs with a separate numbering system to figures in latex?

Question

I am writing a book, and would like to be able to have the photographs labelled with an independent numbering system to my figures. In the text I would refer to, for example, figure X and separately to photograph X, so I want them to have different numbering systems, just as equations and figures do. Is it possible to have a different \begin{figure} environment so that the numbering can be separated?

Answer 1

If you use the memoir class (which extends the book class) then try this (less any typos):

\documentclass{memoir}
\newfloat[chapter]{photo}{lop}{Photo}
\newlistof{listofphotos}{lop}{List of Photos}
\newlistentry{photo}{{lop}{0}
\begin{document}
\tableofcontents
\listoffigures
\listofphotos
\chapter{First}
Text
\begin{figure}
\centering
A FIGURE
\caption{A figure} \label{afig}
\end{figure}
\begin{photo}
\centering
A PICTURE
\caption{A photograph} \label{aphoto}
\end{photo}

Figure \ref{afig} is a figure while \ref{aphoto} is a photo.

\end{document}

The gory details of the above can be found in the memoir documentation (> texdoc memoir) chapter 10.

Answer 2

If you are not using the memoir class, you can use the float package to achieve the same aims, but with a slightly different set of commands:

\documentclass{book}
\usepackage{float}
% Define a new float type for photos
\newfloat{photo}{htbp}{lop}[chapter]
\begin{document}
\tableofcontents
\listoffigures
% add the list of photos
\listof{photo}{List of Photos}
\chapter{First}
Text
\begin{figure}
\centering
A FIGURE
\caption{A figure} \label{afig}
\end{figure}
\begin{photo}
\centering
A PICTURE
\caption{A photograph} \label{aphoto}
\end{photo}

Figure \ref{afig} is a figure while \ref{aphoto} is a photo.

\end{document}