A loupe (pronounced LOOP) is a useful tool to examine everything from gems to jewelry, and looking for signs of wear. For occasional use, it is more practical to hand-hold a loupe rather than learn to hold one in your eye like a monocle. Hand holding a loop also means you do not have to remove eyeglasses if you wear them.

You hold a jewelers loupe between your thumb and forefinger wrapping your fingers around the lens housing to help support the loupe.

If you are examining a small object, hold the object in your free hand. Now brace your elbows against the sides of your body and bring both your hands up towards your face (you may brace your elbows on a desk or table top if you are seated).

Keeping the loupe close to your eye, pivot the hand with the object in and out until you get a sharp focus.

You will avoid eye strain by keeping your free eye open during an examination. This may seem awkward at first but comes easily with very little practice.

( FOCAL LENGTH AND DEPTH OF FIELD )

Focal Length is the distance from the lens in which an object comes into correct focus. Depth of field is the area of the object that will be in focus. The higher the power of magnification from 10X to 20X to 30X, the shorter the focal length and the shorter the depth of field.