Importantly, R, BR, and ER lamps ar

Importantly, R, BR, and ER lamps are formed from blown glass, whereas PAR lamps combine a pressed glass lens with a separate reflector, allowing for more precise optical control. Thus, a greater proportion of PAR lamps are used in demanding applications, such as museum, retail, hospitality, and landscape lighting. PAR lamps—and directional lamps in general—are commonly installed in track heads or downlights, and offer great flexibility because of the variety of available lumen packages and beam characteristics. There are no rigid performance criteria to delineate PAR, R, BR, and ER lamps, although generalized characterizations are possible. For example, conventional PAR lamps tend to have narrower luminous intensity distributions and higher efficacies than BR­ or R­shaped lamps.