What can infrared photometry tell you

Photometric observations made with an infrared photometer-spectrometer (IRPS) over the last 2-1/2 years are reviewed in order to present the variety of uses of infrared photometry in general astronomical research. Boundary conditions are discussed and salient features of the IRPS are outlined, such as chopping facilities to provide rapid sampling of adjacent sky. The electronic aspect of IRPS has been redesigned and has resulted in increased versatility and higher sensitivity than other short-wavelength infrared photometers. In addition, use of a doublet Fabry lens reduces photon shot noise from the surrounding mirror cell, and a push-button control panel makes instrument use simpler and more efficient. Observations are described in regard to late-type stars, dust, molecular hydrogen absorption, accretion phenomena, and nonthermal continua, and future innovations are discussed.