 > I found that the snapshot that I took was too big to fit in my
 > thesis. So, I'd like to know you opinion on:
 >
 > - Is there any way that I can redefine the left margin just for the
 >   picture temporally?
 >
    The chngpage package from CTAN includes an adjustwidth environment
which does this.

Peter W.

Picture too big

> - Is there any way that I can redefine the left margin just for the

You don't need it. \hspace*{-*cm} will work, TeX really don't mind if you try to print outside the margins. To center your picture you could use

\makebox[\textwidth]{picture...}

Ulrike Fischer

Picture too big

> - what is the proper x-geometry(*) window width that is appropriate
>   for Letter paper?

You can resize the photo to fit your page using the \includegraphics command. For example, using the graphicx.sty package:

\includegraphics[width= 6in]{photoname}

Rather than specify an explicit dimension, you can use \linewidth. This is the horizontal distance between your left and right margins. So use of

\includegraphics[width= \linewidth]{photoname}

specifies an x-dimension equal to \linewidth and

\includegraphics[width= 0.5\linewidth]{photoname}

specifies an x-dimension equal to specify some fraction of \linewidth. This approach is independant of paper size and therefore more handy.

Of course, all of this is available in the documentation that should have come with your distribution (ex. look for grfguide.ps).

Brent