Raven - Thank you very much, that was just the answer I was looking for!

"I think all the value inputs (with numbers) desaturate, only the color inputs pass the color data, so just plug the image into the bump input and adjust the value."

I see Poser renders differently; when a Desaturated texture map is plugged into the Bump, VS. when the same image is used with Saturation.

" The gain function is the easiest way to adjust the contrast."

*Thank you very much!  I looked for a Gain node, but did'nt see how to create one?