National Research Council of Canada. National Science Infrastructure
Text, Book Chapter
Astronomers use the term “photometry” to refer to the precise measurement of the apparent brightness of astronomical objects in particular specified ranges of electromagnetic wavelength in and near the optically visible band. Historically, this task has been most commonly carried out with the human eye, photographic plates, photomultiplier tubes, and – most recently as of this writing – charge-coupled devices. At wavelengths significantly shorter or longer than the optical region, different detector technologies must be used, and some other term than “photometry” is often used to name the process.