But carrara is using it as a color map, not a normal map. In fact the only channel that will except the normal menu choice is the bump map channel. You can put a normal map in any other channel in the shader, but it will be used like any other color map/texture.

A normal map is a 3D bump map, not only does it give height like a bump map, it also gives offset and/or angle.

Let me whip up a demo, right now I'm hacked off because for some odd reason sometimes C8.5 likes to pick out random polys on objects; read as genesis clothes, when you use soft select, making it less then worthless.

a: The normal map made black and white, in the alpha channel.

b: The normal map in the alpha channel. As you can see there is no difference.

c: Gray color channel with a normal map in the bump channel.

d: The noraml map map black and white in the color channel and the normal in the bump.

e: The normal map in the color channel.

f: The normal map in the color channel and the bump channel.

As you can see the normal map only works as a normal map in the bump channel set to normal. Other wise it is just a color map like any other texture.