This standard consolidates projection lamps with G5.3 bases into a single standard. The lamps contained in this standard are not to be considered as interchangeable@ although physically they will all fit the common G5.3 lampholders. The photometry of each lamp is dependent upon the system for which it was designed and on the system in which it is used. Representative photometric values are found in Table 2. Tungsten-halogen lamps with G5.3 bases having the ANSI lamp designations EML and EYB are covered.