What is the camera obscura?

Answer 1

well, I know Camera Obscura is the name of a music band. As a photographer, I have never heard the words other than that. I could be wrong though, maybe there's a meaning behind the band name??? I will watch for answers too :)


thanks shy spirit, what an excellent explanation :)

Answer 2

A "camera obscura" is a device that demonstrates the principle that a small hole can act like a lens; If you make a pinhole in a cardboard box, and place it in a bright place, an image of what's outside the pinhole will be projected onto the other side of the box (upside down). The easiest way to see this is to replace the other side of the box with greaseproof paper.

You can do the same thing on a large scale with a building, and several have been built over the years, one of the best of which is at the Cliff House in San Francisco; http://brightbytes.com/cosite/sanfran.html

Answer 3

The camera obscura (Lat. dark chamber) was an optical device used in drawing, and one of the ancestral threads leading to the invention of photography. Photographic devices today are still known as "cameras".

The principle of the camera obscura can be demonstrated with a rudimentary type, just a box (which may be room-size) with a hole in one side, (see pinhole camera for construction details). Light from only one part of a scene will pass through the hole and strike a specific part of the back wall. The projection is made on paper on which an artist can then copy the image. The advantage of this technique is that the perspective is right, thus greatly increasing the realism of the image (correct perspective in drawing can also be achieved by looking through a wire mesh and copying the view onto a canvas with a corresponding grid on it). With this simple do-it-yourself apparatus, the image is always upside-down. By using mirrors, as in the 18th century overhead version illustrated, it is also possible to project a right-side-up image. Another more portable type, as in the second drawing, is a box with an angled mirror projecting onto tracing paper placed on the glass top, the image upright as viewed from the back.

As a pinhole is made smaller, the image gets sharper, but the light-sensitivity decreases. With too small a pinhole the sharpness again becomes worse due to diffraction. Practical camerae obscurae use a lens rather than a pinhole because it allows a larger aperture, giving a usable brightness while maintaining focus.

Some camerae obscurae have been built as tourist attractions, often taking the form of a large chamber within a high building that can be darkened so that a 'live' panorama of the world outside is projected onto a horizontal surface through a rotating lens. Although few now survive, examples can be found in Grahamstown in South Africa, Bristol, Portslade village and Eastbourne Pier in England, Aberystwyth and Portmeirion in Wales, Kirriemuir, Dumfries and Edinburgh in Scotland, Lisbon in Portugal, and Santa Monica and San Francisco in California, Havana in Cuba, Eger in Hungary, and Cádiz in Spain [1]There is even a portable example which Willett & Patteson tour around England and the world.

The principles of the camera obscura have been known since antiquity. It has been claimed that Ibn al-Haitham built a working camera obscura in the 10th century. Its potential as a drawing aid may have been familiar to artists by as early as the 15th century; Leonardo da Vinci once described the camera obscura. Johann Zahn's Oculus Artificialis Teledioptricus Sive Telescopium was published in 1685. This work contains many descriptions and diagrams, illustrations and sketches of both the camera obscura and of the magic lantern.

The Dutch Masters, such as Johannes Vermeer, who were hired as painters in the 17th Century, were known for their magnificent attention to detail. It has been widely speculated that they made use of such a camera, but the extent of their use by artists at this period remains a matter of considerable controversy.
A freestanding room-sized camera obscura used by the art department at the University of North Carolina at Chapel Hill. One of the pinholes can be seen in the panel to the left of the door.

Early models were large; comprising either a whole darkened room or a tent (as employed by Johannes Kepler). By the 18th century, following developments by Robert Boyle and Robert Hooke, more easily portable models became available. These were extensively used by amateur artists while on their travels, but they were also employed by professionals, including Paul Sandby, Canaletto and Joshua Reynolds, whose camera (disguised as a book) is now in the Science Museum (London). Such cameras were later adapted by Louis Daguerre and William Fox Talbot for creating the first photographs.

Answer 4

Camera = Latin for “room”
Obscura = Latin for “dark”
Go into a very dark room on a bright day. Make a small hole in a window cover and look at the opposite wall. What do you see? Magic! There in full color and movement will be the world outside the window — upside down! This magic is explained by a simple law of the physical world. Light travels in a straight line and when some of the rays reflected from a bright subject pass through a small hole in thin material they do not scatter but cross and reform as an upside down image on a flat surface held parallel to the hole. This law of optics was known in ancient times.

The earliest mention of this type of device was by the Chinese philosopher Mo-Ti (5th century BC). He formally recorded the creation of an inverted image formed by light rays passing through a pinhole into a darkened room. He called this darkened room a "collecting place" or the "locked treasure room."

Aristotle (384-322 BC) understood the optical principle of the camera obscura. He viewed the crescent shape of a partially eclipsed sun projected on the ground through the holes in a sieve, and the gaps between leaves of a plane tree.

The Islamic scholar and scientist Alhazen (Abu Ali al-Hasan Ibn al-Haitham) (c.965 - 1039) gave a full account of the principle including experiments with five lanterns outside a room with a small hole.

In 1490 Leonardo Da Vinci gave two clear descriptions of the camera obscura in his notebooks. Many of the first camera obscuras were large rooms like that illustrated by the Dutch scientist Reinerus Gemma-Frisius in 1544 for use in observing a solar eclipse.

The image quality was improved with the addition of a convex lens into the aperture in the 16th century and the later addition of a mirror to reflect the image down onto a viewing surface. Giovanni Battista Della Porta in his 1558 book Magiae Naturalis recommended the use of this device as an aid for drawing for artists.

The term "camera obscura" was first used by the German astronomer Johannes Kepler in the early 17th century. He used it for astronomical applications and had a portable tent camera for surveying in Upper Austria.

The development of the camera obscura took two tracks. One of these led to the portable box device that was a drawing tool. In the 17th and 18th century many artists were aided by the use of the camera obscura. Jan Vermeer, Canaletto, Guardi, and Paul Sandby are representative of this group. By the beginning of the 19th century the camera obscura was ready with little or no modification to accept a sheet of light sensitive material to become the photographic camera. Portable and box camera obscuras from our collection are shown on another page on this site.

The other track became the camera obscura room, a combination of education and entertainment. In the 19th century, with improved lenses that could cast larger and sharper images, the camera obscura flourished at the seaside and in areas of scenic beauty. There are several pages that features images of camera obscura rooms such as this page on US park camera obscuras from our collection. Today the camera obscura is enjoying a revival of interest. Older camera obscuras are celebrated as cultural and historic treasures and new camera obscuras are being built around the world.

Answer 5

It is a method of drawing extremely accurate drawings, by using a dark cage with a rather transparent sheet in the front, where the object is projected really accurately and you can draw it as though you were photographying it. It is atechnique that was used before photography was made common.

Answer 6

shy spirit, it was a good example of copy and paste, I hope you learn too