Discovery Park is pleased
to announce the completion of what we believe
to be the world's
largest camera obscura.
What is a camera obscura you say?
The Camera Obscura (Latin
for dark chamber) was a dark box or room with a
hole in one end. If the hole was small enough, an inverted image would
be seen on the opposite wall. Such a principle was known by thinkers
as early as Aristotle (c. 300 BC). It is said that just before the year
1300, Roger Bacon may have used one to observe solar eclipses. In fact, the
Arabian scholar Hassan ibn Hassan, in the 10th century, described
what could be called a camera obscura in his writings; manuscripts of
his observations are to be found in the India Office Library in
London. The earliest record of the uses of a camera obscura can be
found in the writings of Leonardo da Vinci (1452-1519).
In the mid sixteenth
century Giovanni Battista della Porta (1538-1615)
published what is
believed to be the first account of the possibilities as
an aid to drawing. It is said that he made a huge "camera"
in which he seated his guests, having arranged for a group of actors to
perform outside so that the visitors could observe the images on the
wall. The story goes, however, that the sight of up-side-down
performing images was too much for the visitors; they panicked and
fled, and Battista was later brought to court on a charge of sorcery!
Artists and illustrators
made excellent use of the camera obscura also known
as a pinhole camera. By the mid-sixteenth century, lenses had begun to be
used to increase the brightness and sharpness of the image. And this ancient
device has evolved to what we now have at Discovery Park a forty-inch
diameter lens system that projects a bright, detailed, inverted image
of Mt. Graham on an overhead screen.
The Board of Directors at
Discovery Park sincerely thanks those persons
and groups that made
this exhibit possible:
Dr. Roger Angel,
director of the Steward Observatory Mirror
Laboratory, at the
University of Arizona, for his inspiration
and financial
contributions to the project.
Patrick McGuire, U.
of Arizona post-doctoral research scientist,
and Bruce Jacobsen, U.
of Arizona graduate student, contributed the
design of the
three-lens system,
Rayleigh Optical,
Hextek, and the Steward Observatory Mirror
Laboratory, who made the
lenses.
The Mt. Graham
International Observatory operations team contributed
the design,
fabrication and installation of the lens cell and the projection
screen.
The Arizona
Community Foundation for their confidence and funding
for the
completion of the project.
Next time you are at
Discovery Park stop in the Gov Aker Observatory
and check out the
world's largest Camera Obscura.
See you there!