loepen

Loepen are small magnifying lenses designed for close inspection of small details. In Dutch usage, the term refers to a hand-held or stand-mounted magnifier used in jewelry, watchmaking, philately, numismatics, and laboratory work. A loep typically consists of a single convex lens mounted in a frame that can be brought close to the eye or the object; the user positions the lens a few centimeters from the work surface to achieve magnification. Common magnifications for jewelry and watchmaking range from 3x to 10x; higher magnifications (up to 20x or more) exist for specialized tasks but reduce field of view.

Loepen come in several forms. The hand-held loep is portable and simple, while stand loepen or inspection stands provide a fixed distance and stable positioning. Some loepen are built into headbands or eyewear to keep both hands free. Lenses are usually made of optical glass or high-quality acrylic, and frames are often metal, brass, or plastic.

Proper lighting is important; many users pair a loep with directed illumination, such as LED lights, to improve contrast and reduce shadows. In use, a loep helps reveal surface flaws, tool marks, engravings, grain structure, inclusions in gemstones, or microprinting on banknotes.

Etymology: the Dutch term loep derives from the French loupe. See also magnifying glass, jeweler’s loupe.