Feature Articles

Evolution of the Measurement of Thin Film

Optics has a long history, but the widespread use of thin-film coatings in optics is relatively new. This is a rather abbreviated account of the history of the technology of measurement in thin-film optics.

by Angus MacLeod
Galileo's Lunar Landscape

When Galileo turned his telescope to the heavens in late 1609, astronomy was a science filled with diagrams but lacking actual pictures. The moon, for example, often portrayed as a crescent in medieval and Renaissance works of art, was not pictured as it actually appeared to the naked eye. Prevailing astronomical opinion held that the moon was in fact a perfect sphere.

by Brian S. Baigrie
Photometry Sensing Light and Color

With the proliferation of quality systems in manufacturing such as ISO9000 (a series of standards from the International Organization for Standardization), the accurate measurement of the light and color generated by particular products has become increasingly important. Since light-emitting products are designed to be seen by people or to illuminate other objects that need to be seen, the measurement process must take into consideration the human eye’s response to light. The field of photometry deals with the measurement of light weighted according to human visual response.

by Yoshi Ohno and Steven Brown