330 BC Aristotle
(384-322 B.C.)mentioned the images of a solar eclipse formed on the ground by
sunlight passing through little gaps in tree foliage, and his comments indicate
that he had some grasp of the principles involved.
In view of Aristotle's obvious recognition of the principles, the first camera
could have been constructed by some unknown Greek. More likely, though, it came
more than a thousand years later.
1267 Roger Bacon discussed the camera obscura knowledgeably about and is presumed to have learned about it from the writings of tenth century Arab scholars.
1490 Leonardo da Vinci describes a camera obscura in some detail. In its earliest form, the camera obscura was what the name implies—a dark chamber or room .
1558 The camera obscura was described fully by Giovanni Battista della Porta. In the first edition of his Magiae Naturalis, he specified that a conical hole be installed in the shutter of a darkened room and that the image be shown on a white screen. He said that the image would appear upside down and reversed from left to right, and that the image size would be proportional to the distance from the hole to the viewing screen—all of which are equally valid observations for the cameras we use today. Porta recommended that the camera obscura image be used as a guide for drawing and then went on to invent a method for producing an erect image using lenses and curved mirrors.
1550 The application
of lenses to the camera obscura after 1550 was a significant step. The image
could then be made both sharper and more brilliant because a lens can admit
much more light than a simple hole and can also focus the light rays to finer
points. Camera's began to be refined in design and construction as more and
more people became interested in them By about 1575, the first movable cameras
appeared . They were, at first, wooden huts or tents that completely enclosed
the viewer and viewing screen. Later, more elaborate models, such as sedan chairs,
were constructed.
From that point on, the evolution was rapid. Smaller models were designed, which
permitted the operator to view or trace the image from outside the main enclosure.
Finally, completely portable cameras appeared.
1676 A reflex
camera, one in which the image is reflected up onto a t opmounted viewing
screen by an inclined mirror behind the lens, was built in 1676; a balland
socket mount (like some modern tripod heads) appeared in 1680; and a telephoto
lens was installed in a camera obscura in 1685. The camera was ready, but for
what?
Timeline
of photochemical discoveries
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© Werner Hammerstingl
1998