Loupe

A loupe (/ˈluːp/ LOOP) is a simple, small magnification device used to see small details more closely. Unlike a magnifying glass, a loupe does not have an attached handle, and its focusing lens(es) are contained in an opaque cylinder or cone or fold into an enclosing housing that protects the lenses when not in use. Loupes are also called hand lenses.

Three basic types of loupes exist:

Loupes are used in a number of industries, notably the jewelry trade, watchmaking, photography, printing, dentistry, education and ophthalmology. Loupes are also used in academia and life sciences, such as geology and biology. Amateur naturalists may also find a hand lens or a loupe a useful tool when looking at or identifying species. They are also used in numismatics and stamp collecting.

Jewelers typically use a monocular, handheld loupe in order to magnify gemstones and other jewelry that they wish to inspect. A 10× magnification is good to use for inspecting jewelry and hallmarks and is the Gemological Institute of America's standard for grading diamond clarity. Stones will sometimes be inspected at higher magnifications than 10×, although the depth of field, which is the area in focus, becomes too small to be instructive. The accepted standard for grading diamonds is therefore that inclusions and blemishes visible at 10× impact the clarity grade.

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