Really i think it depends on the colors and tones of the original. Either technique could be better in that case. However, here is another way to make a B&W from a color photo that could produce better results Go to the RGB channel palette and click on the red, green and blue channels one at a time, which turns only that channel on. If you see a particular channel that has a nice B&W range 1) select all and copy 2) click on the top RGB channel to turn all the channels back on 3) switch to the layers palette and paste (which makes the channel from step 1 a new layer in B&W