The photographic news

• Bandzählung: 29.1885
• Erscheinungsdatum: 1885
• Sprache: Englisch
• Signatur: F 135
• Vorlage: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: SLUB Dresden
• Rechtehinweis: Public Domain Mark 1.0
• URN: urn:nbn:de:bsz:14-db-id1780948042-188500006
• PURL: http://digital.slub-dresden.de/id1780948042-18850000
• OAI: oai:de:slub-dresden:db:id-1780948042-18850000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Bemerkung: Seite I-II fehlen in der Vorlage. Paginierfehler: Seite 160 als Seite 144 gezählt.
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

730 THE PHOTOGRAPHIC NEWS. LNOvEMER 13, 1885. County, and State of New York, Optician.—Dated Septem ber 15th, 1885. This invention has reference to an improved lens for spectacles and other optical instruments, and the invention consists of an optical lens that is ground to a greater degree of curvature at its shorter meridian or axis, and to a lesser degree of curvature at its longer meridian or axis, either to a convex or concave surface according as the lens is intended to magnify or diminish. The lens is ground at one side in such a manner that the radius of the shorter axis or meridian is smaller than the radius of the longer axis or meridian, whereby a greater degree of curvature is produced in the direction of the shorter axis than in the direction of the longer axis. The result is an elliptical lens, the surface of which is ground either convex or concave, but with different radii for the different axis of the lens. The radius of the shorter meridian may be, for instance, twelve feet, while the radius of curvature of the longer meridian is twenty feet. A lens is thereby obtained that magnifies or diminishes to a greater degree at the meridian of the shorter' axis than at the meridian of the longer axis. The other surface of the lens may be ground either plane, convex, concave, conical, elliptical, cylindrical, prismatic, or otherwise, according to the combination that is desired to be made with the front surface. A lens is thereby obtained that corresponds in a higher degree than the lenses heretofore in use to the peculiar shape of the eye, and which is thereby better adapted to correct the imperfect vision of the same. 2241. Frederick Woodward Branson, of Leeds, in the County of York, for “ Improvements in photographic shutters.”— Dated February 18th, 1885. The Patentee says : — My improvements refer to that class of shutter which is described in the Specification of a Patent granted to Richard Reynolds and myself dated April 2nd, 1883, No. 1050, such shutter being also employed under the patent granted to me dated 5th February, 1884, No. 2767, such shutter being also em ployed in my applications for patents dated June 11th, 1884, No. 8852, and December 22nd, 1884, No. 16793 and No. 16794, and the present invention refers to the employment of a second drop which fits so as to move freely in the same slide as the drop used in the hereinbefore mentioned photographic shutter. This second drop is placed in the slide below the original, and on its upper portion a hinged or solid frame is provided ; such frame forms the opening or aperture through which the light passes for photographic purposes. The aperture in the framework is covered in the first instance by the lower or solid part of the second drop, and both drops are held by a catch ; on the catch being released, the lower drop is instantaneously forced downwards Dy the upper drop actuated through gravity, spring, or other convenient means, the opening therein passing quickly in front of the lens, followed by the upper drop, which shuts off the light by passing in front of the lens. The slide is so arranged at the bottom part as to allow the second drop to fall entirely out of it, its position being taken up by the first or upper drop. The second drop is attached to the framework of the photographic shutter by an elastic cord or its equivalent. When preferred, the upper and lower drops may be combined. Patents Granted in America. 329,385. William W. Grant, Brooklyn, N.Y. “ Camera.” Filed June 28, 1883. No model. Claim.—1. The method of producing photographic negatives of an object or sitter and surroundings or secondary matter, by impressing on a sensitive plate the image of the object or sitter, by means of the light from the same passing through the lens, and at the same time impressing surroundings or secondary matter upon said sensitive plate by light transmitted through a transpar ent plate or medium containing the matter to be impressed, the light for which purpose being admitted independently of that passing through the lens at the front of the sensitive plate. 2. The method of producing photographic plates of an object with engraved lines, etch, stipple scenic, or such other secondary and combined effects, showing throughout the image and the border surrounding the image, by juxtaposing a transparent or semi-transparent medium embodying one part of the secondary matter in front of the sensitive plate, and juxtaposing another transparent or semi-transparent medium embodying the further matter, to be combined behind the sensitive plate, and transmit ting the light passing from the object through a lens and the said transparent or semi-transparent medium in front to the sen sitive plate, and transmitting light (independently of that passing through the front lens) through the said transparent or semi transparent medium juxtaposed behind to the sensitive plate. 3. The method herein described of producing photographic negatives of an object or sitter and a suitable background by im pressing the image of the object or sitter upon the sensitive plate in front by the reflected light from the same passing through the lens of a camera, and printing upon the said'plate from the rear, the image of the background by transmitted light passing through a transparent positive. 4. The method herein described of producing photographic negatives embracing the image of an object or sitter and a suit able background, the same consisting in first posing the object or sitter before a non-actinic background in front of the camera, receiving the image on a faint, transparent positive on ground glass or opaline to determine its location, then blocking out the image in non-actinic paint on a transparent masking-plate, and then impressing the respective images from the front and rear by reflected and transmitted light. 5. The combination, in a photographic camera, of the front and rear sections having an intervening recess for the plate-holder, and the plate-holder having sliding covers front and rear, and adapted to receive the sensitive plate and a transparent positive, the camera being provided with translucent windows front and back, for the admission of light in addition to the lens. 6. The combination, with the camera, consisting of front and rear sections having an intervening frame-holding recess, of the sliding block and its operating mechanism located in the rear sec tion, and the standards and nippers adapted to carry a masking- plate. 7. The combination, with the front section of the camera, of the rear section thereof, constructed in two hinged parts, and the mechanism for carrying the masking-plate. COMMUNICATIONS FROM THE PHOTO-CHEMI CAL LABORATORY OF THE IMPERIAL HIGH SCHOOL OF BERLIN. BY DR. W. H. VOGEL. Removal of Silver Stains.—The use of cyanide of potas sium for the removal of silver stains has a disagreeable side, especially when there are cuts or abrasions of the skin. Other means for the removal of the stains have been proposed, such as iodine in iodide of potassium, or perchloride of iron. It has been found that the same preparation which has done such excellent service as a reducing agent for gela tine negatives, can be used with advantage: a solution containing ferricyanide of potassium and hyposulphite of soda. Either dissolve a few crystals of the ferricyanide in the usual hypo solution, or make up a preparation as follows 5 to 10 cubic centimetres of a solution of the ferricyanide containing 1 to 5, are mixed with about 50 cubic centimetres of hyposulphite solution. This preparation has done good service in freeing our hands from silver stains. Instead of using the mixed solutions, the spots may be treated first with the ferricyanide solu tion, and then with the hyposulphite. The above method has the advantage of involving the use of no poisons, and not causing injury to the clothes. The solution containing ferricyanide of potassium and hyposulphite of sodium is not permanent, as the yellow colour soon disappears, and the fluid becomes turbid from the deposition of sulphur, just as if an acid had been added. The fluid then gives the reaction of sulphates with chloride of barium. It is scarcely necessary to say that after the discolouration has taken place the solu tion is useless, but it can be restored to activity again by an addition of fresh ferrocyanide. Any blue stains result ing from the use of the solution can be easily removed by a dilute solution of caustic soda. Experiments with Magnesium Torches.—El the suggestion of Herr Meydenbauer, magnesium torches for photo graphic use have been made by the Schering Chemical Manufacturing Company. They are 50 centimetres long, and in the case of experiments made in this Institution,