deletions | additions       diff --git a/subsubsectionImages_.tex b/subsubsectionImages_.tex  index 53c9b5e..485e40e 100644  --- a/subsubsectionImages_.tex  +++ b/subsubsectionImages_.tex 
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changes as you first account for the bias, and then the flat field.  The way you will be removing the bias and flat field effects is by  using the IRAF procedure {\tt ccdproc}. We first need to load some IRAF packages. Type:  \begin{verbatim}  cl> noao  cl> imred  cl> ccdred  \end{verbatim}  Before we do anything, we need to set the parameters of ccdproc, so  that it will do what we want. To do this, type {\tt epar ccdproc}  (epar = `edit parameters'). You will see a screen with a lot of options