^ George Eastman House Archived at the Wayback Machine.It consists simply of a cylinder of flint glass, or long plano-convex lens whose focus is its ovm plain surface, to which the photograph is attached with Canada balsam." The image seen through it is magnified about three hundred times." and "The lens used for toy micropliotographs resembles the Stanhope lens, but is not cut down in the centre to form a diaphragm. ^ a b c d A history and handbook of photography (1877) Author: Tissandier, Gaston, 1843-1899 Subject: Photography Photography Publisher: New York : Scoville Manufacturing Quote: "It is a miniature microscope with considerable magnifying powers.^ a b The Photographic Journal By Royal Photographic Society of Great Britain Jan.51-54 Archived at the Portuguese Web Archive ^ a b c d e f g h The Strad Magazine October 2005 pp.^ a b c d e f g h i j Focal encyclopedia of photography By Michael R.In modern times, the most common stanhopes are usually gold or silver crosses with Christian prayers in the microphotograph. Stanhope lenses are still manufactured to this day, but they are not produced according to Dagron's methodology. In 1998, after Roger's death, the workshop was closed and its equipment dismantled and sold. In 1972 the factory, run by Roger Remond, produced the last stanhope lens made by the traditional methods. He was succeeded in the management of the factory by his son Roger. In the early twentieth century Eugène Reymond took control of Dagron's stanhope lens factory in Gex, France. In 1864 Dagron became famous when he produced a stanhope optical viewer which enabled the viewing of a microphotograph 1 square millimetre (0.0016 sq in), (equivalent in size to the head of a pin), that included the portraits of 450 people. That same year, Dagron displayed the devices at the 1862 International Exhibition in London, where he got an "Honourable Mention" and presented them to Queen Victoria. In 1862 Dagron published his book Cylindres photo-microscopiques, montés et non montés sur bijoux. Dagron also developed mail order marketing techniques for his viewers. In 1860 Dagron obtained the patent for his viewers under the title Bijoux Photomicroscopiques. In 1862 he had 150 employees and was manufacturing 12,000 units a day. In August 1859 he exhibited them at the International Exhibition in Paris where they met with great success. As of June 1859, Dagron's factory was manufacturing the stanhopes, mounted in jewellery and souvenirs. The success of his viewers enabled Dagron to purpose-build a factory dedicated to their production. The viewers were first introduced to the general public at the 1859 International Fair in Paris. Mass production and fame ĭagron's efforts met with great success. The violin Stanhopes featured the portraits of famous people such as Paganini, Tourte, and Stradivari. The Stanhope optical viewers were mounted inside the bows of violins by French violin maker Jean-Baptiste Vuillaume, probably using Dagron's methods and equipment. It’s a little joke which causes much amusement." "If you look at the middle of the pearl eye in each nut you will see a little lens, through which you can see Paganini, Tourte, and Stradivari. Dagron also designed a special microphotographic camera which could produce 450 exposures approximately 2 by 2 millimetres (0.079 in × 0.079 in) on a 4.5-by-8.5-centimetre (1.8 in × 3.3 in) wet collodion plate. The modified Stanhope lens was small enough to be mounted in all manner of miniature artifacts such as rings, ivory miniatures, wooden toys etc. The sectioned lens could magnify the microphotograph three hundred times, so that the viewing of the microphotographs no longer required a bulky and expensive microscope. The viewing lens cylinder is located at the smaller diameter opening This arrangement enabled the picture to be focused. This produced a plano-convex lens, where Dagron was able to mount the microscopic photograph on the flat side of the lens using Canada balsam as adhesive. Dagron modified the Stanhope lens by sectioning the normally biconvex Stanhope lens and introducing a planar section so that the plane was located at the focal length of the convex side of the cylindrical lens. In 1857 Dagron solved the problem by inventing a method of mounting the microphotographs at the end of a small cylindrical lens. The main disadvantage of Dancer's method was that the viewing of the microphotographs required a microscope which was at the time an expensive instrument. This resulted in a microphotograph about 3 square millimetres (0.0047 sq in) in area. In 1851 John Benjamin Dancer invented microphotographs using a collodion process and a microscope converted to a camera. A stanhope in the form of a miniature telescope Invention and development
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