Viewing DSS Fits Files

[Bill Cotton]

Andrew John Walker writes:
 > Peter Teuben <teuben at astro.umd.edu> writes:
 > 
 > >Tom McGlynn wrote:
 > >> 
 > >> FITSview did seem to be a very nice and powerful tool
 > >> for displaying FITS image data and I anticipate that I will
 > >> be using it now that I've downloaded it onto my PC.
 > 
 > >I must have been doing something very basic wrong. I found FITSview
 > >a bit annoying (on unix, never tried the win* versions):
 > >It's most basic operation, changing the colortable interactively, was done in
 > >another widget using sliders or so. I tried moving the mouse
 > >in the window, with and without pressing down a variety of
 > >keyboard buttons, and nothing appeared to change contrast/colors etc.
 > >Perhaps I'm too spoiled by that and the client-server nature of saoimage
 > >and SAOtng. Are there functional differences between the unix
 > >and win* versions of FITSview. I noted that month after month it
 > >is the top download from the NRAO ftp archive. I must be missing
 > >something (apart from the blue screen of death of course)
 > 
 > >Btw, saoimage is also pretty nice with DSS images. Displaying full
 > >WCS info etc.
 > 
 > 	The last time I used Fitsview you had to reload the image for
 > the minimum and maximum pixel range to work. However brightness and contrast
 > should work immediately.
 > --
   Let me point out that the FITSview family is primarily targeted at
the general public for which the major consideration is simplicity and
obvious controls - obscure keyboard controls of things like brightness
and contrast are explicitly avoided.  Sliders are obvious - keys are
not in the postliterate era.  FITSview is not intended as a competitor
to SAOimage.  I hope that the FITSview family is useful to
professional astronomers but they are not its primary market.
   The general public supports us through their taxes and the very
least we can do is share our pretty pictures with them.  FITSview is
aimed at people who want to go beyond the gif or jpeg renditions of
images from which most the astronomy has been removed.  We've made the
sky accessable on the internet but we also have to provide the tools
so that people can take advantage of this.

   The most recent version of all of the FITSviewers, by default, looks
at the image to decide the appropriate range of pixel values to
display based on the sky and noise levels.  It doesn't always get it
right but this really cuts down on the reloads. 
   All of the FITSviewers understand DSS and IRAF CD-matrix
coordinates as well as WCS and will give a WCS display of the
coordinates.
   The differences among the Windows, Unix and Apple versions are
relatively minor.  The Windows version has a print button, the others
do not; the Windows version has a toolbar, the others do not and, of
course, the Windows help system is vastly superior to anything
(including html) on its competitors.  However, the real reason that
the Windows version of FITSview dominates the ftp fetches is that
Windows dominates the computing world; most computer users have never
even heard of Unix.

-Bill Cotton