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An image dissector is a camera tube that creates an " electron image " of a scene from photocathode emissions ( electrons ) which pass through a scanning aperture to an anode, which serves as an electron detector.
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image and dissector
Video camera tubes in the early days of television used the photoelectric effect, for example, Philo Farnsworth's " Image dissector " used a screen charged by the photoelectric effect to transform an optical image into a scanned electronic signal.
Although he made many contributions that were crucial to the early development of all-electronic television, he is perhaps best known for inventing the first fully functional all-electronic image pickup device ( video camera tube ), the " image dissector ", the first fully functional and complete all-electronic television system, and for being the first person to demonstrate such a system to the public.
* Germany experiments with a flying bomb guided by a television camera, created by Fernseh, using both the Superikonoscope and the Farnsworth image dissector.
Behind this grid system, an image dissector tube ( photomultiplier type detector ) with a sensitive field of view of about 38 arc-sec diameter converted the modulated light into a sequence of photon counts ( with a sampling frequency of 1200 Hz ) from which the phase of the entire pulse train from a star could be derived.
Other hardware components were supplied as follows: the beam-combining mirror from REOSC at Saint Pierre du Perray ; the spherical, folding and relay mirrors from Carl Zeiss AG in Oberkochen ; the external straylight baffles from CASA in Madrid ; the modulating grid from CSEM in Neuchatel ; the mechanism control system and the thermal control electronics from Dornier Satellite Systems in Friedrichshafen ; optical filters, the experiment structures and the attitude and orbit control system from Matra Marconi Space in Velizy ; instrument switching mechanisms from Oerlikon-Contraves in Zurich ; the image dissector tube and photomultiplier detectors assembled by the Dutch Space Research Organisation, SRON in The Netherlands ; the refocusing assembly mechanism designed by TNO-TPD in Delft ; the electrical power subsystem from British Aerospace in Bristol ; the structure and reaction control system from Daimler-Benz Aerospace in Bremen ; the solar arrays and thermal control system from Fokker Space System in Leiden ; the data handling and telecommunications system from Saab Ericsson Space in Gothenburg ; and the apogee boost motor from SEP in France.
Stars were observed as the satellite rotated, by a sensitive region of the image dissector tube detector.
* September 7-Philo Farnsworth's electronic image dissector television camera tube transmits its first image at his laboratory at 202 Green Street in San Francisco.
All-electronic designs based on the cathode ray tube, such as Vladimir Zworykin's Iconoscope and Philo T. Farnsworth's Image dissector, supplanted the Baird system by the 1940s and remained in wide use until the 1980s, when cameras based on solid-state image sensors such as CCDs ( and later CMOS active pixel sensors ) eliminated common problems with tube technologies such as image burn-in and made digital video workflow practical.
The term may apply specifically to a dissector tube employing magnetic fields to keep the electron image in focus, an element lacking in Dieckmann and Hell's design, and in the early dissector tubes built by American inventor Philo Farnsworth.
Their experiments on the image dissector were announced in the volume 8 ( September 1927 ) of the popular magazine Discovery and in the May 1928 issue of the magazine Popular Radio.
The introduction of a multipactor in October 1933 and a multi-dynode " electron multiplier " in 1937 made Farnsworth's image dissector the first practical version of a fully electronic imaging device for television.
The optical system of the image dissector focuses an image onto a photocathode mounted inside a high vacuum.
The image dissector has no " charge storage " characteristic ; the vast majority of electrons emitted by the photocathode are excluded by the scanning aperture, and thus wasted rather than being stored on a photo-sensitive target, as in the iconoscope or image orthicon ( see below ), which largely accounts for its low light sensitivity.
Unlike the Farnsworth image dissector, the Zworykin iconoscope was much more sensitive, useful with an illumination on the target between 4ft-c ( 43lx ) and 20ft-c ( 215lx ).
The production and commercialization of the super-Emitron and image iconoscope in Europe were not affected by the patent war between Zworykin and Farnsworth, because Dieckmann and Hell had priority in Germany for the invention of the image dissector, having submitted a patent application for their Lichtelektrische Bildzerlegerröhre für Fernseher ( Photoelectric Image Dissector Tube for Television ) in Germany in 1925, two years before Farnsworth did the same in the United States.
image and is
Westbrook further bemoans the Southern writers' creation of an unreal image of their homeland, which is too readily assimilated by both foreign readers and visiting Yankees: `` Our northerner is suspicious of all this crass evidence ( of urbanization ) presented to his senses.
Life is further characterized, in antithesis to Piepsam, as animal: the image of a dog, which appears at several places, is first given as the criterion of amiable, irrelevant interest aroused by life considered simply as a spectacle: a dog in a wagon is `` admirable '', `` a pleasure to contemplate '' ; ;
By `` image '' is meant not only a visual presentation, but also remembered sensations of any of the five senses plus the feelings which are immediately conjoined therewith.
This favorable image of America in the minds of Russian men and women is still there despite years of energetic anti-American propaganda ''
The `` conventional '' image of a particular time and place is not necessarily congruent with the image of the facts as established over the years by scholarly and scientific research.
For here if anywhere in contemporary literature is a major effort to counterbalance Existentialism and restore some of its former lustre to the tarnished image of the species Man, or, as Malraux himself puts it, `` to make men conscious of the grandeur they ignore in themselves ''.
That picture of the American prairie is as indelibly fixed in the memory of those who have studied the conquest of the American continent as any later cinema image of the West made in live-oak canyons near Hollywood.
The most articulate Republicans are those who, in their desire to get back at Mr. Kennedy, already have created the image of a Republican leadership which is reluctant to assist the distressed and the unemployed, and which is even more unwilling to help old people who need medical care.
In establishing conditions of self-help, it is important that we not expect countries to remake themselves in our image.
Consider a simple, closed, plane curve C which is a real-analytic image of the unit circle, and which is given by Af.
Moreover, from the definitive transformation of intercepts on the generators of Af, it is clear that the only points of Q at which a line can meet its image are the points of Aj.
The most obvious of these is the quadratic complex of tangents to Q, each line of which is transformed into the entire pencil of lines tangent to Q at the image of the point of tangency of the given line.
It is interesting that a 1: 1 correspondence can be established between the lines of two such pencils, so that in a sense a unique image can actually be assigned to each tangent.
Hence, thought of as a line in a particular plane **yp, any tangent to Q has a unique image and moreover this image is the same for all planes through L.
image and camera
* 2007: On September 16, 2007, hunter Rick Jacobs captured an image of a supposed Sasquatch by using an automatically triggered camera attached to a tree, prompting a spokesperson for the Pennsylvania Game Commission to say that it was likely an image of " a bear with a severe case of mange.
Marker also reminds the reader that only one short scene in La Jetée is of a moving image, as Marker could only borrow a movie camera for one afternoon while working on the film.
" His slow motion, fast motion, and other camera techniques were a way to dissect the image, Mikhail Kaufman stated in an interview.
The image of each person's face is then projected onto a two-way mirror positioned in front of the lens of the other's camera.
Alternatively, the image can be photographically recorded by exposing a photographic film or plate directly to the electron beam, or a high-resolution phosphor may be coupled by means of a lens optical system or a fibre optic light-guide to the sensor of a CCD ( charge-coupled device ) camera.
Using camera obscura, it was possible to project a moving image, but there was no means of recording the image for later viewing.
To do this he built a special printer in which the negative running through a projector was projected into the gate of a camera through a special lens giving a same-size image.
This meant that the actors played a scene up to a line marked on the ground nine feet from the camera lens, which meant that they were shown cut off at the waist in the image.
In Poor Little Rich Girl ( 1917 ) a camera shot tilting sideways is intended to convey delirium, and by 1918 the idea had got to Russia, in Baryshnya i khuligan ( The Lady and the Hooligan ), where the Hooligan's infatuation with the Lady is conveyed by his Point of View of her splitting into a multiply superimposed image.
Whenever a drastic change to the image occurs, such as when switching from one camera shot to another, or at a scene change, a keyframe must be created.
Occasionally, an image is deliberately windowboxed for stylistic effect ; for example, the documentary-style sequence of the film Rent suggest an older-format camera representing the 4: 3 aspect ratio, and the opening sequence of the Oliver Stone film JFK features pillar boxing to represent the 1960s era 4: 3 television footage.
Although critics have claimed that the photograph is of a dog swimming towards the camera ( possibly carrying a stick ), researcher Roland Watson rejects this interpretation and suggests there is an eel-like head on the right side of the image.
In addition to, or instead of, directly viewing the object through the eyepieces, a type of sensor similar to those used in a digital camera is used to obtain an image, which is then displayed on a computer monitor.
In Shards of Honor, Cordelia borrows a holovid reporter ’ s camera, but in most of the books a computer / holovid screen seems to have a built-in camera which can record an image or video.
The lack of strobe ( as opposed to flicker ) is due to the higher sampling rate of the camera relative to the speed of movement of the image across the film plane.
Dziga Vertov claimed in his 1924 manifesto, “ The Birth of Kino-Eye ” that “ the cinema-eye is cinema-truth .” To paraphrase Hilmar Hoffman, this means that in film, only what the camera ‘ sees ’ exists, and the viewer, lacking alternative perspectives, conventionally takes the image for reality.
Daegling and Schmitt noted problems of uncertainties in subject and camera positions, camera movement, poor image quality, and artifacts of subject.