Types and terms of magnifying glasses

Some people need magnifying glasses in certain circumstances, such as reading a newspaper, a book, the fine print on a map, a menu as well as examining a diamond or gemstone. Currently, there are various kinds of magnifiers, including Head Visor magnifiers and pendant necklace magnifying glasses. The first criterion is that the type of magnifying one chooses should match the use of it.

Magnifying glasses are now provided in different styles and designs. And different people need specific magnifying power. For instance, ordinary people may use a 5x hand held magnifier to examine windshield for defects. A pocket 10x folding magnifying glass is helpful for a border protection department as well as a police department. In addition, 20x jeweler loupes can be used by a county department of agriculture to examine crops for insect and blight problems.

For general reading, hand held magnifiers are convenient and helpful. For newspapers or books, people always use a magnifier with 3x or 6x magnification and 3 or 4 inch diameter. And for finer print materials, magnifiers with 8x or 20x magnification are needed. For people with low vision, magnifying glasses in standard design are not competent and they may resort to electronic vision aids which can offer greater magnification.

The following is the explanation of several terms of magnifying glasses. Magnifying power means the ability of a magnifying glass to increase the visual size of an object. A magnifying lens simply bends light in a special way and makes an image looks larger than an actual object. The X indicates the magnifying power. For instance, a 3x glass triples an image and 4x magnifiers magnify an object 4 times.

Focal length or working distance is another way to classify magnifying glasses. This element represents the distance that should be set between the magnifier and an object in order to get the optimal magnification effect. For example, a lens with 2x magnification and 5” focal length means that the lens can provide double magnification when it is held at a distance of 5” from the object.

Field of view simply indicates the size of the area that a person sees through the glasses. Depth of field is the distance that a magnifier can be moved above an object and still maintains focus ability. In general, depth field decreases as magnification power increases.