Tone Mapping

Can some explain in simple terms exactly what tone mapping is, why you would do it and exactly how you go about doing it. I'm reading this HDR book and it keeps talking about the importance of scaling back from 32 bit to 16 bit but doesn't explain how to do it.

TIA

Basically, it's just adjusting the image to get "what you want" (there are no standards as far as taste) by changing the gamma levels, depth of blacks, midtone contrast, saturation, blend between different exposures, when working with 3 or 5 exposures HDR.

Now I don't know how simple this is, but to compare it with the CS5 image<adjustment<highlights-shadows would be about the closest thing I can think of. If you ever tried to play with this adjustment, it's about the closest thing to tone mapping I can think of.

Hope this helped a little.

Now, how to do it, just get in there and experiment with "Photomatix" or in CS5 the tone mapping filters. You'll have to find the balance between the effect you're after and good taste...