There are variables to achieve what you are looking for. I shoot in BnW mode with my S3 when I want black and white. I am a purest that way. I don't mind giving this information out freely as I have stated before. I overexpose the image for my black and white by 1/2 stop. This is just me as many experts will say shoot it right on and post process it.
On my overexposure technique I will adjust levels to bring the blacks back as overexposure will lean towards being flat in contrast. The blown out look comes from taking the midtones out by adjusting the levels and getting the pop I like when bringing back the blacks. In PS, conversion of an rgb image you can change it to lab color and click on the lightness channel and watch it pop that way as well.
Just one side of many ways I can go about a black and white J T signature style head shot. Hope this helps.