the invention is generally accomplished providing a silver halide emulsion comprising silver halide grains and a tellurium compound represented by formula i : tel . sub . n x . sub . 2 wherein l is thiourea or substituted thiourea , n is 2 or 4 , x is cl , br , i , ocn , scn , secn , tecn , or n 3 or formula ii ## str1 ## wherein x is cor , csr , cnr 2 , cr , car , pr 2 , p 2 r is alkyl or aryl .