Process for forming light-sensitive silver halide crystals

A process for forming light-sensitive silver halide crystals by adding silver ion in the form of a silver salt aqueous solution and halide ion in the form of a halide salt aqueous solution to a solution containing bromide ion in the presence of a protective colloid, which comprises producing seed crystals containing multiple twin crystal grains during a crystal nuclei-forming period, maintaining the pBr of the system at about 4.8 to 2.0 during at least the first third of a subsequent crystal-growing period, and increasing the rates of silver ion and halide ion addition to levels at which the crystal growth becomes about 30 to 100% of the critical crystal growth rate, including gradually increasing the concentration of said silver salt aqueous solution and said halide salt aqueous solution during said crystal-growing period.