/ˈkæmərə, ˈkæmrə/ɒbˈskyʊərə/
–noun
a darkened boxlike device in which images of external objects, received through an aperture, as with a convex lens, are exhibited in their natural colors on a surface arranged to receive them: used for sketching, exhibition purposes, etc.
"ancestor of the photographic camera. The Latin name means "dark chamber," and the earliest versions, dating to antiquity, consisted of small darkened rooms with light admitted through a single tiny hole. The result was that an inverted image of the outside scene was cast on the opposite wall, which was usually whitened. For centuries the technique was used for viewing eclipses of the Sun without endangering the eyes and, by the 16th century, as an aid to drawing; the subject was posed outside and the image reflected on a piece of drawing paper for the artist to trace. Portable versions were built, followed by smaller and even pocket models; the interior of the box was painted black and the image reflected by an angled mirror so that it could be viewed right side up. The introduction of a light-sensitive plate by J.-N. Niepce created photography."
Originally, the camera obscura was a large room with only a small opening to allow an image to appear against the opposite wall. This method has been around a very long time, with such a simple method of operation that it is really hard to place it exactly. Seriously, thousands of years ago in ancient china they had these things - not just since the middle ages, aka the 60's.
Larger camera obscuras built for amusement are all around the place; once a spectacle, the camera obscura structures of the last century are now a novelty to those who could simply pull out a cellphone and take a 10 megapixel image. Coming in a variety of sizes and shapes, these structures usually have a similar periscope-type lens to produce an image on a flat surface near the ground that allows people to see the image outside the enclosure.
Portable camera obscuras had been used for a long time as well to aid artists in painting more realistically. These devices typically used a single lens and a mirror to reflect the subject upwards onto tracing paper, which the artist would then outline, or, more simply, the artist would enclose himself in a wooden box with a lens to face the model, and the artist would use the tracing paper to outline the model. I feel like the man in the first image is compensating for something.
Camera obscura's can be made in a room, in a box, or in a shoe - as long as you have a dark space and an aperture to focus light, an image should appear on the other side. In our class, we were assigned to make our own camera obscura, something that I found to be an absolute joy as I love to build things.
My design used a +10 diopter from a lens filter and another piece of glass from an old lens, giving a very sharp, very nice view on the ground glass on the back of the camera obscura. The glass also allowed me to have a larger opening in the front, however my focal point was rather close to the lens, and the focusing range goes from 2 feet to infinity with a slide of about an ince, positioning the lens closer or further from the ground glass.
