A substantially inert ultraviolet absorbing compound, and photographic elements containing them, which compound has a peak absorption at less than 400 nm and being of formula : ##STR1{HEAD ~ ##} wherein: {TAIL ~ X} is O or NR8, Z represents the atoms necessary to complete a 5 membered or 6 membered heterocyclic ring which includes X and N, and the 3 position of the pyrazolone ring may independently be substituted or unsubstituted 