Re: Best B & W conversion
I agree with Holgaman that is why I don't like the B&W adjustment layer it tends to give out too much unwanted noise.
What I do normally is use various masked layers of the channel mixer adjustment layer set to monochrome (in the lower left corner you check the box) and adjust individually for each part of the photo (each separated by its painted mask). After that I use hue/saturation adjustment layer and drive the saturation to 0 so If there are parts that the channel mixer layers didn't cover this desaturates it so I don't have to fill them out.
I have also thought about just doing different curves layers and then just use a hue/saturation layer to desaturate the image, but since the channel mixer has worked so well I haven't tried it yet.