Here are some suggestions to fix your current situation:
Note the subfloat notation:
\subfloat[<LoF>][<subcaption>]{<body>}
Since your <body> consisted only of a \label command, the <subcaption> (actually, the <LoF> entry) had to wrap around something that is "very thin", causing it to not typeset properly. See page 4 of the subfig documentation for an explanation of this.
Also, the \label should be included in the <body>.
If you put the entire \subfloat within a fixed-width environment, the caption will wrap according to that width. This can be achieved via a minipage environment, for example. In the following minimal example, I've defined two new commands:
\vertfig[<subcaption>]{<body>}% For vertical figure placement
\horizfig[<subcaption>]{<body>}% For horizontal figure placement
that you can use to replace the traditional \subfloat. \vertfig typesets its contents in a 5in-width minipage, while \horizfig does so in a 3in-width minipage. Both dropped the second optional argument of \subfloat[..][..]{...}, since it didn't seem to matter to you.
As you can see, no fixed-width \captionsetup is required, since the captions wrap to the box they're contained in.
\documentclass[11pt]{article}
\usepackage[a3paper]{geometry}% http://ctan.org/pkg/geometry
\usepackage{graphicx}% http://ctan.org/pkg/graphicx
%\usepackage{caption}% http://ctan.org/pkg/caption
\usepackage{subfig}% http://ctan.org/pkg/subfig
\newsubfloat{figure}
\pagestyle{empty}% No header/footer
\newcommand{\vertfig}[2][]{%
\begin{minipage}{5in}\subfloat[#1]{#2}\end{minipage}}
\newcommand{\horizfig}[2][]{%
\begin{minipage}{3in}\subfloat[#1]{#2}\end{minipage}}
\begin{document}
\begin{figure}[ht]
\centering
\vertfig% \subfloat
[This is probably the biggest tiger you will ever see in your life.
The caption associated with this subfloat should span more than one
line even though the width of the contents is 5in.]
{\includegraphics[width=5in]{tiger}\label{fig:vizcardfront}}
\vertfig% \subfloat
[Data submission form on the back of the view guide.]
{\includegraphics[width=5in]{tiger}\label{fig:vizcardback}}
\caption{The visibility monitoring view guide.}\label{fig:viewcard}
\end{figure}
\begin{figure}[ht]
\centering
\horizfig%\subfloat
[Here is another picture of the tiger, this time a little smaller.
It is still very fierce-looking, right?]
{\includegraphics[width=3in]{tiger}\label{fig:plantcam}}
\hfill
\horizfig%\subfloat
[A HOBO$\textsuperscript{\textregistered}$ data logger for air and soil data.]
{\includegraphics[width=3in]{tiger}\label{fig:logger}}
\caption{Automatic data collection instruments.}\label{fig:autodata}
\end{figure}
\end{document}
geometry was merely used to set the paper size to a3paper.
The trick is to put your graphics in a \vcenter box. The rest is just bureaucracy: \vcenter requires math mode, and \hbox prevents the image from taking the whole line width.
\documentclass{article}
\usepackage{graphics}
\newcommand\myincludegraphics[1]{%
\ensuremath{\vcenter{\hbox{\includegraphics{#1}}}}%
}
\begin{document}
\begin{figure}
\centering
\renewcommand\arraystretch{3}
\begin{tabular}{rcl}
description&\myincludegraphics{gfx/test}&description\\
description&\myincludegraphics{gfx/test}&description\\
description&\myincludegraphics{gfx/test}&description\\
description&\myincludegraphics{gfx/test}&description\\
&0\hfill 5\hfill\hfill 15\hfill\hfill\hfill 30&min
\end{tabular}
\caption{A caption}
\label{fig:figure}
\end{figure}
\end{document}
EDIT: This version deals with descriptions of different lengths, keeping the images horizontally centered no matter what.
The main idea is to put the left descriptions in a \llap (so it will stick out to the left, while pretending to 0pt wide) and the right descriptions in a \hbox to 0pt (these will pretend to be 0pt wide but stick out to the right --- by the way, \rlap doesn't work well in this case).
The rest is to make things easy to use. Package array allows to you automatically but arbitrary code around your entries using < and >. Furthermore, it allows you to define new column types. So I put all the \llap and \hbox magic in the column type C, and included the vertical positioning magic in there as well. This should make things easier to use.
Since the middle column type was redefined, the old timeline didn't work anymore, so I used \multicolumn to reset the middle column type for the last line back to a simple c. While at it, I have packed it all in a macro to save some further typing. (Maybe we should make it extremely fancy by making LaTeX position the numbers on the timeline automatically? :-))))
\documentclass{article}
\usepackage{graphicx}
\usepackage{array}
\newcolumntype{C}{%
>{\llap\bgroup}c<{\egroup}%
>{$\vcenter\bgroup\hbox\bgroup}c<{\egroup\egroup$}
>{\hbox to 0pt\bgroup}c<{\egroup}%
}%
\newcommand\timeline[1]{&\multicolumn{1}{c}{#1}&min}
\begin{document}
\begin{figure}
\centering
\renewcommand\arraystretch{3}
\begin{tabular}{C}
description long&\includegraphics{gfx/test}&desc\\
description&\includegraphics{gfx/test}&description very very extremely long\\
description&\includegraphics{gfx/test}&desc\\
description&\includegraphics{gfx/test}&descript\\
\timeline{0\hfill 5\hfill\hfill 15\hfill\hfill\hfill 30}
\end{tabular}
\caption{A caption}
\label{fig:figure1}
\end{figure}
\begin{figure}
\centering
\renewcommand\arraystretch{3}
\begin{tabular}{C}
description long&\includegraphics{gfx/test}&desc\\
description very very extremely long&\includegraphics{gfx/test}&desc\\
description&\includegraphics{gfx/test}&desc\\
description&\includegraphics{gfx/test}&descript\\
\timeline{%
\makebox[0pt][c]{0}\hfill
\makebox[0pt][c]{5}\hfill\hfill
\makebox[0pt][c]{15}\hfill\hfill\hfill
\makebox[0pt][c]{30}}
\end{tabular}
\caption{A caption}
\label{fig:figure2}
\end{figure}
\end{document}
UPDATE 2: Automatic tick-placement (for fun) and fixed intercolumn spacing (for real):
\documentclass{article}
\usepackage{graphicx}
\usepackage{array}
\newcolumntype{C}{%
>{\llap\bgroup}c<{\egroup\hskip 1em}%
@{}>{$\vcenter\bgroup\hbox\bgroup}c<{\egroup\egroup$}@{}
>{\hskip 1em\hbox to 0pt\bgroup}c<{\egroup}%
}%
\usepackage{etoolbox}
\newcommand\timeline[1]{%
&\multicolumn{1}{@{}c@{}}\begingroup
\global\let\do\firstT
\docsvlist{#1}%
\endgroup&min%
}
\def\firstT#1{\makebox[0pt][c]{#1}\xdef\previousT{#1}\global\let\do\otherTs}
\def\otherTs#1{%
\count0=#1\relax \advance\count0-\previousT\relax
\loop\ifnum\count0>0 \typeout{\the\count0}\advance\count0-1 \hfill\repeat
\makebox[0pt][c]{#1}\xdef\previousT{#1}%
}
\begin{document}
\begin{figure}
\centering
\renewcommand\arraystretch{3}
\begin{tabular}{C}
description long&\includegraphics{gfx/test}&desc\\
description&\includegraphics{gfx/test}&description very very extremely long\\
description&\includegraphics{gfx/test}&desc\\
description&\includegraphics{gfx/test}&descript\\
\timeline{0,5,15,30}\\
\timeline{0,10,20,30}\\
\timeline{0,20,25,30}\\
\end{tabular}
\caption{A caption}
\label{fig:figure1}
\end{figure}
\begin{figure}
\centering
\renewcommand\arraystretch{3}
\begin{tabular}{C}
description long&\includegraphics{gfx/test}&desc\\
description very very extremely long&\includegraphics{gfx/test}&description\\
description&\includegraphics{gfx/test}&desc\\
description&\includegraphics{gfx/test}&descript\\
\timeline{0,2,4,6,8,10,20,30}
\end{tabular}
\caption{A caption}
\label{fig:figure1}
\end{figure}
\end{document}
UPDATE: left-aligned left description
I don't know how to do this automatically, because one needs to know the width of the widest left description in advance. A semi-automatic solution is to set this length in advance, just before the tabular environment --- the column definiton then puts the left description in a \hbox of the given width.
\documentclass{article}
\usepackage{graphicx}
\usepackage{array}
\newlength\widestLeftEntryLength
\newcolumntype{C}{%
>{\llap\bgroup\hbox to \widestLeftEntryLength\bgroup}c<{\hss\egroup\egroup\hskip 1em}%
@{}>{$\vcenter\bgroup\hbox\bgroup}c<{\egroup\egroup$}@{}
>{\hskip 1em\hbox to 0pt\bgroup}c<{\egroup}%
}%
\begin{document}
\begin{figure}
\centering
\renewcommand\arraystretch{3}
\settowidth\widestLeftEntryLength{description very very extremely long}
\begin{tabular}{C}
description long&\includegraphics{gfx/test}&desc\\
description very very extremely long&\includegraphics{gfx/test}&description\\
description&\includegraphics{gfx/test}&desc\\
description&\includegraphics{gfx/test}&descript\\
\end{tabular}
\caption{A caption}
\label{fig:figure2}
\end{figure}
\end{document}
Best Answer
Note that we need to use the optional argument of
\captionboxhere so\\will work inside it. Furthermore there is a bug in the current version of thecaptionpackage so the combination of\phantomsubcaptionand\labelwill produce an unwanted space. This will be fixed in the very next version 3.3 of thecaptionpackage. Until then one can place the\phantomcaptions at the end of the box as workaround:(
\captionboxis not documented yet but is available since version 3.2 of thecaptionpackage; its syntax is equal to\subcaptionboxbut will produce a regular caption instead.)