Preparation method of regular silver (halide) bromide or silver bromoiodide light-sensitive emulsions and material comprising said emulsions

Method to prepare a light-sensitive regular silver bromide or silver bromoiodide emulsion comprising the following steps:

• precipitating silver bromide or silver bromoiodide by addition of an aqueous solution of silver nitrate and halide salt(s) through a double-jet or triple-jet technique in colloidal silica having a particle size from 0.003 .mu.m to 0.30 .mu.m as a protective colloid
• in the presence of an onium compound, excluding ammonium (NH.sub.4 +) compounds, and in the absence of any polymeric compound capable of forming hydrogen bridges with colloidal silica, said polymeric compound including gelatin or its derivatives but not including polythioether compounds, wherein a ratio by weight of said colloidal silica to said onium compound(s) between 3 and 30 is present,
• controlling nucleation and growth of the silver bromide and silver bromoiodide by means of variable flow rate(s) of the aqueous solutions of silver nitrate and halide salts and/or by means of constant pAg-values during the said nucleation and growth in order to determine the number of nuclei quantitatively during said nucleation and to avoid renucleation during said growth,
• desalting and redispersing the silver bromide or bromoiodide,
• chemically ripening the silver bromide or silver bromoiodide and
• adding colloidal silica in order to obtain a ratio by weight of the colloidal silica to the amount of silver bromide or silver bromoiodide, expressed as the equivalent amount of silver nitrate, to a value of at least 0.03 at every moment throughout precipitation.