The Photographic Performance of Silver Bromoiodide Emulsions Containing Triiodide

The photographic properties of silver bromoiodide emulsions were discussed when different methods were applied in adding the potassium triiodide aqueous solution into the reaction vessel during the period of precipitation. The sensitivity and contrast of the two emulsions doped with potassium iodide and potassium triiodide respectively were compared. Triiodide could increase the contrast significantly. The contrast decreased when triiodide was added near the surface of the grain,or when the mole ratio of iodide to iodine increased.