black and white conversion

I only have a few minutes tonight but wanted to get an image up that i shot a couple hours ago.
I set up two flashes for this shot. One was placed to camera left and acted as the main light. It was pretty far over, mabey at about 70 degrees. The second flash was placed to the right and just behind her a bit. I played with the shutter until the sky was where i wanted it, i think it ended up at about 1/250 sec.
I brought the image into photoshop camera raw plug in and tweaked the white balance and exposure and brought up the black slider quite a bit to make the shadows strong. It looked pretty good in color but lastly i thought i would bring the saturation slider all the way to the left to check it out in black and white. There it stayed. I felt it was a much stronger image this way.
The foreground grass and top of the sky were a bit on the light side so i duplicated my background layer first of all. Then with the top, new layer, highlighted i went to filter - distort - lens correction and applied a vignette. I made the amount quite high (slider moves to the left) and moved the midpoint to the left also to bring the darkness into the image. I then made a layer mask on this layer and painted in black over her face just to make sure that none of the vignette darkened her. I didn't paint in the mask around her feet as they were ok to go darker.
I smart sharpened about 50% with a radius of 1 and was done.