Search results
Results From The WOW.Com Content Network
In contrast, a modern LCD or DLP projector often uses an Ultra-high-performance lamp which has a higher luminous efficacy and lasts for thousands of hours. [5] A drawback of that technology is the warm up time required for such lamps. Older overhead projectors used a tubular quartz bulb which was mounted above a bowl-shaped polished reflector.
A projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen. Most projectors create an image by shining a light through a small transparent lens , but some newer types of projectors can project the image directly, by using lasers .
Simulation of a spinning zoopraxiscope An early projector and seats from a movie theater. The main precursor to the movie projector was the magic lantern.In its most common setup it had a concave mirror behind a light source to help direct as much light as possible through a painted glass picture slide and a lens, out of the lantern onto a screen.
The Lower Paleolithic period lasted over 3 million years, during which there many human-like species evolved including toward the end of this period, Homo sapiens.The original divergence between humans and chimpanzees occurred 13 (), however interbreeding continued until as recently as 4 Ma, with the first species clearly belonging to the human (and not chimpanzee) lineage being ...
Many manufactured slides were produced on strips of glass with several pictures on them and rimmed with a strip of glued paper. [9] The first photographic lantern slides, called hyalotypes, were invented by the German-born brothers Ernst Wilhelm (William) and Friedrich (Frederick) Langenheim in 1848 in Philadelphia and patented in 1850. [9] [10 ...
The slide images were too small for unaided viewing, and required enlargement by a projector or enlarging viewer. Photographic film slides and projectors have been replaced by image files on digital storage media shown on a projection screen by using a video projector , or displayed on a large-screen video monitor .
Victor offered many models of 16mm projectors, most with only minor variations, but prior to military contracts won during World War II, all were made and sold in very small numbers, from 20 units to usually no more than a couple of thousand units. The company was a large producer of lantern slides using their "Featherweight" method- a one ...
Vitascope was an early film projector first demonstrated in 1895 by Charles Francis Jenkins and Thomas Armat. They had made modifications to Jenkins' patented Phantoscope, which cast images via film and electric light onto a wall or screen. The Vitascope is a large electrically-powered projector that uses light to cast images.