Comet Hale-Bopp is, without doubt, one of the most important objects for cometary science which has ever been observed. The light curve is well-observed from a heliocentric distance 7.2 AU and some information is available at distances as great as 17 AU. This allows the photometric evolution of the comet to be studied as different volatiles dominate the activity. Three different phases of activity are seen as the heliocentric distance reduces during 1996: the initial phase of very fast brightening, characterized by a r -5 law; a “standstill” in the light curve when the brightening law reduced to r -1, which coincides with the initiation of water sublimation at r ~ 4 AU; and a further phase of more rapid brightening with an r -3.5 law, similar to the mean for comets classed as “fairly new”, which initiated at r ~ 4 AU.