Reader's Comments - Index of - Free

Pinhole Photography
Landschaft von der Sonne beleuchtet wird and man bringt auf der
gegenüberliegenden Seite in der Wand einer nicht von der Sonne
gotroffenen Wohnung ein kleines Löchlein an, so werden alle erleuchteten
Gegenstände ihr Bild durch diese Öffnung senden und werden umgekehrt
erscheinen". [1]
In 1475 the Renaissance mathematician and astronomer Paolo Toscanelli
placed a bronze ring with an aperture in a window in the Cathedral of
Florence, still in use today. On sunny days a solar image is projected
through the hole onto the cathedral's floor. At noon, the solar image bisects
a "noon-mark" on the floor. The image and noon-mark were used for telling
time (Renner 1995:6).
In 1580 papal astronomers used a pinhole and a similar noon-mark in the
Vatican Observatory in Rome to prove to Pope Gregory XIII that the spring
equinox fell incorrectly on 11 March rather than on 21 March. Two years
later, after careful consideration, Pope Gregory XIII corrected the Julian
calendar by 10 days, thus creating the Gregorian calendar (Renner 1995:7).
Giovanni Battista della Porta (1538–1615), a scientist from Naples, was
long regarded as the inventor of the camera obscura because of his
description of the pinhole (lensless) camera obscura in the first edition of his
Magia naturalis (1558). His description has received much publicity, as did
his camera obscura shows, but he was by no means the inventor.
The first published picture of a pinhole camera obscura is apparently a
drawing in Gemma Frisius' De Radio Astronomica et Geometrica (1545).
Gemma Frisius, an astronomer, had used the pinhole in his darkened room
to study the solar eclipse of 1544. The very term camera obscura ("dark
room") was coined by Johannes Kepler (1571–1630). At his time, the term
had come to mean a room, tent or box with a lens aperture used by artists to
draw a landscape. The lens made the image brighter and focused at a certain
distance. Thus this type of camera differed from the pinhole camera obscura
used by Frisius in 1544. In the 1620s Johannes Kepler invented a portable
camera obscura. Camera obscuras as drawing aids were soon found in many
shapes and sizes. They were used by both artists and amateur painters.
During the 19th century several large scale camera obscuras were built as
places of education and entertainment. The meniscus lens, superior to the biconvex
lens, improved the quality of the the projected images. Several
buildings or towers with camera obscuras remain today: The Camera
Obscura at Royal Mile, Edinburgh; the Great Union Camera at Douglas, Isle
http://www.photo.net/photo/pinhole/pinhole (4 of 28)7/3/2005 2:15:39 AM