OF THE ROGER N. CLARK

Preface
To stand beneath a dark, crystal-clear,
moonless country sky is an awe-inspiring experience.
Those thousands of stars, many larger
than our own Sun, can make us feel small
indeed. It seems possible to see to infinity,
though we cannot reach beyond arm's length.
The beauty of the universe defies description.
Turn a telescope on a seemingly empty
part of sky and swarms of new stars come into
view - and possibly a faint glow of fuzzy
nebulosity. Yet the heavens are subtle. Imagine
that the fuzzy patch at the threshold of
visibility is really a trillion suns - a galaxy
larger than our own, in which our Sun is but a
tiny speck. Incomprehensible; yet somehow
we try. Seeing that galaxy first-hand, even
through a small telescope, is much more inspiring
than the large, beautiful photograph
in the astronomy book back indoors. Nothing
can compare to viewing the universe directly.
The city dweller looks up at night and if
lucky, sees a few stars and thinks "That's
nice". But show that same person a very dark
country sky and he or she will be awe-struck.
Such a sky can be so spectacular that the
Milky Way casts a shadow, and so many
stars may be visible that even experienced
observers have trouble finding constellations.
Even after many years as an amateur
astronomer, I am still awe-struck on a dark
moonless night. I was a very active amateur
in the late 1960s and early 1970s, making
both visual and photographic observations of
everything within reach. By 1971, I had
observed all the Messier and many NGC objects
with an 8-inch telescope. I was especially
interested in astrophotography, and taking
pictures of the heavens consumed most of my
spare time. Visual observing seemed just an
enjoyment, something to do while getting
warmed up for those long hours guiding the
telescope for that prize astrophoto.
In the late 1970s, my amateur career came
to a standstill while I worked on a Ph.D. in
planetary science. By 1982 the amateur bug
was biting hard again, and all my oid,
pleasurable observing memories brought me
back to active status.
Now that I had seen "everything", I was
willing to spend time making detailed drawings
of what I saw. I began a literature search
fo r material on how the eye performs in lowlight-level
conditions·
the handbooks for amateur astronomers
available today, I found a surprising lack of
information on observing deep-sky objects, or
on what can actually be seen of them through
telescopes.
The typical handbook devotes considerable
space to observing the Moon and
planets, but when the subject of galaxies and
nebulae comes up, it has less to say. Usually
it just recommends that because these objects
are faint, low power should be used. Such
works have inculcated the idea among
amateur astronomers that one should have a
"richest-field telescope" and low-power
eyepieces fo r deep-sky work.
This concept seemed wrong to me. My
impression at star parties in the dark skies of
the Cascade Mountains of Washington state
was that an 8-inch f/IO telescope gave a more
detailed view of most objects than richest
field telescopes of the same or even slightly
larger aperture! This was one reasorr I built
an 8-inch f/1l.5 Cassegrain. Although I had
started to build an 8-inch f/4.5, my opinions
changed so much that I decided on the longer
focal length partway through the project. I
heard a few experienced amateur astronomers
express the same thoughts-but none
could give a good reason why high f/ratio
telescopes seem to work better on faint objects.
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