Civil Rights
Movements, leaders, victories and the continuing fight for equality.
q2K BHP
Black History Portal
THE BHP WIRE —
HIDDEN TRUTHS
What's New!
Explore the people, places, events, achievements, struggles and stories that shaped our journey.
Movements, leaders, victories and the continuing fight for equality.
Innovation, patents, science, technology and world-changing contributions.
Pioneers, champions, Negro Leagues, records, activism and excellence.
Meet the people whose lives, choices and achievements shaped the journey.
Black towns, communities, institutions and places where history happened.
Moments that changed communities, movements, institutions and the nation.
In August 1908, a white mob attacked Springfield, Illinois’s Black community, destroying homes and businesses and lynching two Black men. National outrage over the violence helped spur the movement that created the NAACP the following year.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
A transparency, also known variously as a viewfoil or foil (from the French word "feuille" or sheet), or viewgraph, is a thin sheet of transparent flexible material, typically polyester (historically cellulose acetate), onto which figures can be drawn. These are then placed on an overhead projector for display to an audience. Many companies and small organizations use a system of projectors and transparencies in meetings and other groupings of people, though this system has been largely replaced by video projectors and interactive whiteboards.
A Projection panel (also called overhead display or LCD panel) is a device that, although no longer in production, was used as a data projector is today. It works with an overhead projector. The panel consists of a translucent LCD, and a fan to keep it cool. The projection panel sits on the bed of the overhead projector, and acts like a piece of transparency. The panels have a VGA input, and sometimes Composite (RCA) and S-Video input. Later models have remotes, with functions such as 'freeze' which lets you freeze the image, useful for when you want to leave something on the screen whilst you do other things. Earlier models only had 640x480 resolution, while newer ones had up to SVGA resolution. Proxima, one maker of the panels, included a magic wand and sensor, which worked with the sensor detecting where you put the wand, to create and interactive effect, the equivalent of today's smart boards. Although they are not produced anymore, used panels can be purchased for a fraction of the price of a data projector. The panels are quite dim, as they do not let a great deal of light through, so brightness can be a problem, even with a powerful overhead projector.
In photography, the terms reversal film, slide film, positive film, and transparency film describe a type of photographic film that produces a positive image on a transparent film base. In place of negatives and printed photographs, reversal film produces diapositive photographs, known as diafilm and dia images. A diapositive slide is a mounted frame of transparency film intended for large-format projection of the image onto a screen by a slide projector. Such large-format projection permits many spectators to view the diapositive image at one time. The usual transparency-film format is the 35 mm slide, wherein one frame of film is mounted into a 2 in. ×2 in. square made either of cardboard or of a plastic material. Reversal film is produced in format sizes that range from 35 mm to roll film to 8 in. ×10 in. sheet film. Moreover, specialized photographic processing laboratories produce diapositive slides from digital-camera images in formats such as the JPEG, from computer-generated presentation graphics, and from images of physical materials such as fingerprints, microscopic evidence, paper documents, astronomic images, etc. Reversal film also is used as motion picture film in the 16 mm, Super 8 and 8 mm cine film formats, and produces a positive-image film that was originated in the cinematographic camera. In terms of film-production costs, such a cinematographic application of reversal film is more cost-effective than filming with negative film that then must be developed into a positive-image film for projection in a cinema.
A large-format slide projector (also often called large-format projector or large-image projector) is a kind of slide projector for large image projection which has a very powerful light source (up to 12 thousand watts using arc lamps). The light source generates a lot of heat even when filtered to only visible light; the projected transparency is protected from overheating by the heat being distributed across its large area, and cooling fans. Slide formats include 18 × 18 cm (7.1 × 7.1") or 24 × 24 cm (9.4 × 9.4").
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →The Greenwood District.