[vsnet-chat 2654] Vickers atlas on CD-ROM

[Brian Skiff <bas@lowell.edu>]

     This note from Tom Polakis may be of interest to supernova-hunters
dealing with the problem of obtaining good archive images.

\Brian

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Date: Mon, 07 Feb 2000 20:50:27 -0700
To: 
From: Tom Polakis <polakis@sprintmail.com>
Subject: Vickers Deep Space CCD Atlas CD-R


There have been rumors about that the Vickers CCD atlas was out print.  Not
only are they false, but his product is alive and well on a new CD.  I
learned this from the "New Products" feature in Astronomy magazine, and
sent him a check the next day.

I'm sure most on this list are familiar with the atlas.  It is a collection
of over 4000 images in northern and southern volumes by John Vickers and
Alex Wasselif.  The images have an uncanny property of giving a similar view
to what a 25- to 36-inch telescope will show visually at a dark site.  This
is especially the case for galaxies, which dominate the book, as they do in
any list of objects of the sky.  In my past five years, I can't remember a
session of serious obserivng in which I didn't compare his images to the
image on my retina.

The book printing was good, but as expected, the images on Vickers' CD are
significantly better.  Where a page would show a haze, the screen image
shows faint spiral arms.  Tiny knots in these arms that elude the paper are
preserved  on the CD.

Vickers' CD is stored almost exclusively as Adobe Acrobat (.pdf) files.  He
provides the reader software.  The low-resolution .pdf files, which are
suitable for screen viewing, consume 45 Mb.  The high-resolution .pdf files
for the entire atlas take up 250 Mb, and will come out looking just like
book pages on a good printer.  The Acrobat format has its advantages, but I
would have preferred simple .tif or even .jpg files arranged by object
number rather than full page views.  He does provide one token .tif file
from each page.  Go figure.

The real attraction to me is in the ability to present his images as white
on black.  Photoshop will do a "rasterized import" of the .pdf file, and it
can be inverted from there.  The results are very pleasing.  This CD on a
laptop at your observing site is the next best thing to a T1 connection to
the DSS.  If you'd like to see some results for one page, view them at:

http://vsnet.psiaz.com/polakis/vickers/pg29n.jpg
and http://vsnet.psiaz.com/polakis/vickers/pg29n_invert.jpg  (inverted)

They are both 150 Kb.  If you have the book, hold page 29 up to the screen
and compare the spiral arm detail in NGC 1048, the presence of NGC 1023A at
the east end of its big brother, and the dust lane in NGC 1032.  Quite an
improvement!

Vickers is as quiet about his home page as he has been about his atlas.
It's at:

http://vsnet.gis.net/~vickers

Tom

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Tom Polakis
Tempe, AZ
Arizona Sky Pages
http://vsnet.psiaz.com/polakis/

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