What do you mean by 'conversion,? Done in post processing by Photoshop or the like? I used to work in BW in my film days, but with digital I've been stuck in color and do what I can in post processing. Images work out OK, but prints don't, at least not with my printers. Here, the graininess doesn't seem to add to the image. Seems to take away too much of the sharpness. But your sure got a lot of shadow detail in what had to be a dark area.