Types of Lenses in a Magnifying Glass
A magnifying glass is a tool used for a wide variety of professional and amateur purposes. In its simplest form the magnifying glass is a round lens enclosed by a metal or plastic frame and affixed to a handle. This type of magnifying glass is frequently associated with the mythical sleuth Sherlock Holmes. The tool is used to enlarge, or magnify, an object to make it easier to see its details.
History
English inventor, scientist and philosopher Roger Bacon is credited with inventing the modern magnifying glass in 1250 A.D. However, the instrument's history goes much farther back, into antiquity. The seven-volume "Book of Optics" by Iraqi scientist Ibn al-Haytham described the magnification properties of the convex lens early in the 11th century, and the Greek playwright Aristophanes refers to the "burning-lens" in his play "The Clouds in the 5th Century B.C."
Benefits
The lenses of contemporary magnifying glasses are typically constructed of either glass or acrylic. Glass lenses tend to deliver a clearer image because they allow light to pass through more easily. Glass magnifying glasses can be quite heavy and are subject to breakage. Acrylic lenses do not provide the same level of clarity as glass magnifiers, but they are much lighter and much less likely to shatter. Most magnifying glasses, particularly for amateur use, are made of acrylic.
Considerations
A magnifying glass, also referred to as a hand lens, utilizes a convex lens to produce an enlarged image of the object being observed. "Convex" means the lens bulges outward in the middle, as opposed to a concave lens, which narrows in the middle.
Function
Typical household uses of a hand lens may be to enlarge the print of books, newspapers, or magazines to make reading easier. Hobbyists utilize hand lenses for delicate detail work when doing cross-stitch, needlework, model-building, numismatic and philatelic examination. Professionals such as jewelers, geologists, and art dealers use magnifying glasses for close examination of objects to determine their origin or authenticity.
Types
A loupe, sometimes called a jeweler's loupe, is a type of magnifying glass that is similar in composition to a microscope. The jeweler's loupe typically provides magnification of 10 times. The lens on a loupe is usually much smaller than that on a lollipop-style magnifying glass and requires both the object being observed and the eye of the observer to be very close to the loupe for proper magnification.
Tags: magnifying glasses, magnifying glass, being observed, convex lens, Glass magnifying, hand lens, jeweler loupe
