Abstract: The invention provides novel photographic compositions comprising a propene isomer of the formula ##STR1## wherein A B or E, each individually represent hydrogen, or an electron withdrawing group, selected for example from --CN, --NO.sub.2, --SO.sub.2 R, --SO.sub.2 NH--, --CO.sub.2 R, --COR, --CONHR, --CONHAr, --CF.sub.3 halogen, amino, aryl, aralkyl, alkyl, cycloalkyl, alkyl (carbonyl)oxy, aryl (carbonyl)oxy, carboxy, alkoxycarbonyl, aryloxycarbonyl, carbamomyl, acyl, alkylaminocarbonyl, arylaminocarbonyl, alkoxycarbonylamino, acylamino, ureido, alkylsulphonylamino, arylsulphonylamino, sulphamoylamino, alkylsulphonyl, arylsulphonyl, sulphamoyl, imido, alkylthio, arylthio and heterocycles; the invention also provides a propene isomer of the formula I wherein D represents a group of the formula Ar--L--wherein Ar is a phenyl group optionally substituted with one or more substituents, and --L-- is a linking group incorporating a lone pair of electrons; and A, B, E and X are defined as R is above defined.