preview-latex: Basic modes of operation

 
 1.4 Basic modes of operation
 ============================
 
 preview-latex has a number of methods for generating its graphics.  Its
 default operation is equivalent to using the 'LaTeX' command from
 AUCTeX.  If this happens to be a call of PDFLaTeX generating PDF output
 (you need at least AUCTeX 11.51 for this), then Ghostscript will be
 called directly on the resulting PDF file.  If a DVI file gets produced,
 first Dvips and then Ghostscript get called by default.
 
    The image type to be generated by Ghostscript can be configured with
 
      M-x customize-variable RET preview-image-type RET
 
 The default is 'png' (the most efficient image type).  A special setting
 is 'dvipng' in case you have the 'dvipng' program installed.  In this
 case, 'dvipng' will be used for converting DVI files and Ghostscript
 (with a 'PNG' device) for converting PDF files.  'dvipng' is much faster
 than the combination of Dvips and Ghostscript.  You can get downloads,
 access to its CVS archive and further information from its project site
 (http://savannah.nongnu.org/projects/dvipng).