By Merav Schejtman-Gilai.
History of Binoculars
The first binoculars that were made of two parallel telescopes, were created in 1608 by the Dutch optician Hans Lipperhey. They had magnification capability of X3. One year later Galileo Galilee (1564-1642), the Italian philosopher and mathematician improved the telescope to a magnification of X30. Johann Kepler (1571-1630) invented binoculars, which gave a much wider field of view. But, because they had two convex lenses the picture that was seen was inverted. In about 1617 Anton Schyrle (1597-1660), inserted an extra lens and the image was re-inverted it is called a terrestrial telescope. In 1758 John Dollond of England solved the main problem that plagued all binoculars till then- color aberration. He invented a lens made from two lenses cemented together. Each lens was made from a different type of glass. This is the achromatic (color free) lens that is still in use today. In the mid 18th century a Venetian optician named D. Salva (1710-1762) invented the bridge that connected two small Galilean telescopes. This bridge is still in use today. A very important development occurred in the mid 19th century. An Italian gunnery officer- Ignazio Porro (1801-1875) found a way to use the Keplerian binoculars and turn the picture over using prisms. This change brought forth a new generation of prismatic binoculars with a wide field of vision and larger magnification possibilities and made Galilean binoculars almost obsolete.
Structure
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1. Objective lenses and bell 2. Eye cup and lenses 3. Body 4. Bridge. Solid or with hinge. 5. Focus wheel |
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Opera Glasses
We find Opera glasses mentioned in a London advertisement as early as 1730. These were monoculars; small Galilean telescopes. The body was decorated with gems, enamel, ivory and other decorations.
It was not until 1823 in Vienna, that the first binocular opera glasses were invented and put into use. It was built of two cylinders connected with a bridge. Each eye-tube extended independently for focusing. Two years later in Paris, Pierre Lemiere improved on these, and created the center focus wheel, which allowed the focusing of both eyes together. The making of fine opera glasses entailed kn
owledge not only in optics. Each glass was worked on by painters, goldsmiths and other artists. By the second half of the 19th century they had become essential fashion accessories for theatre- goers. Many opera glasses were given as gifts and tributes, as can be learned from the inscriptions found on many of them.
It was not until 1823 in Vienna, that the first binocular opera glasses were invented and put into use. It was built of two cylinders connected with a bridge. Each eye-tube extended independently for focusing. Two years later in Paris, Pierre Lemiere improved on these, and created the center focus wheel, which allowed the focusing of both eyes together. The making of fine opera glasses entailed knowledge not only in optics. Each glass was worked on by painters, goldsmiths and other artists. By the second half of the 19th century they had become essential fashion accessories for theatre- goers. Many opera glasses were given as gifts and tributes, as can be learned from the inscriptions found on many of them
Types of Opera Glasses
There are two main types of Opera Glasses: Monocular and binocular. There are 4 subgroups of binocular glasses: Lorgnette: binoculars with an extended handle, miniature (up to 3-4cm in height), unusual: such as Jealousy Glasses, that had a sideways mirror to allow discreet observation of other people and regular. Most of the production of Opera glasses was done on the European mainland: France Austria and Russia.
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| 5X35 Austrian lorgnette binoculars. Body and handle are made from a rare brown mother of pearl | A 3x27 American aluminum binoculars with decorated handle |
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