publication date: 1976-05-18; filing date: 1973-07-09Direct-positive silver halide emulsions comprising fogged silver halide grains and having adsorbed to the surface of said grains an electron-acceptor have improved stability and speed when subsequent to fogging of said grains and addition of the said electron acceptor the pH of the emulsion is lowered, preferably below pH 6.Mass production of silver halide recording material for full colourholographi