Chapter 03: Correct use of a hand lens

Abstract

A hand lens is a powerful tool for the identification of wood, but like all tools it must be used correctly to take full advantage of its powers. The hand lens has two main parts, a lens that magnifies the object of interest (generally we use 10X or 14X lenses in wood identification; a 14X lens is recommended for use with this manual) and a housing to hold and protect the lens (Figure 1). Unlike a microscope, which is able to focus at different distances depending on the specimen and the configuration of the various lenses, thus requiring much adjusting, a hand lens has a fixed focal length. There is only one distance between the lens and the object that will produce a sharp image. This distance, generally only 1–4 cm, is easily found by examining a coin or other familiar object with the lens. Most hand lenses have no “front” or “back” to them; you can look through either side of the lens at a specimen.

Parent Publication

• Identification of Central American Woods/de las Especies Maderables de Centroamerica

Citation

Wiedenhoeft, Alex. 2011. Chapter 03: Correct use of a hand lens. In: Identification of Central American Woods. 2011. Forest Products Society, Madison, WI. Publication #7215-11, ISBN 978-1-892529-58-9. pp. 21-22.