Raytracing soft shadows

Hello guys, Im studying light and try to make some soft shadows using raytracing, but i played with all parameters and i only get noise soft shadows when i raise the samples value. If i raise only the soft value, nothing happens. Its possible to make soft shadows with raytracing? or make the noise soft shadows of raising samples and blurry it? Thanks for the help.

Try raising the soft value to something like 2, and the sampling to 10.

Thanks radialroonie, it worked, i just needed to make more experiments. Taking advantage of this topic, blender 2.49 can simulate GI (Global Ilumination)? Thanks again.