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Commonly Used Terms
Magnification: The degree to which the
specimen (viewed object) is enlarged. This is normally expressed by a
number followed by an "X" which signifies power. To determine the
magnifying power based on the lens diopter use the formula below.
Diopter: Identifies the refractive (light bending) capacity of a
lens. Note: the rated magnifying power of a lens is based on the
specimen being viewed at the full focal length. |
Focal Length: The distance from the center of the
lens (or combination of lenses) to the specimen when it appears at its
maximum size without distortion.
Helpful Hints
As a magnifying power increases, the focal length and
field of view decrease in size (see chart of focal length).
Eyes should be 8-10 inches above when viewing comfort
and proper ergonomic position to avoid neck and shoulder muscle fatigue.
Generally, 5-diopter is the maximum diopter that can be used for
assembly work (with an 8 inch focal length for most tools to fit under
for work, such lenses are for inspection purposes only). |
