This is an illustration of Russell's B&W conversion.
I added an additional Levels adjustment layer right above the background image.
The "filter" layer (actually a Hue/Saturation adjustment) is adjusted just as
if you are changing color filters on a camera loaded with B&W film.
The original conversion from color left a very pale (light) barn.
I made some adjustments to the Master Hue/Saturation, then
maded additional adjustments to the RED channel to deepen the tones.