Quoted from BagginsBill:

"Look I've explained this before but for some reason it doesn't reach everybody.

Normal maps are a hack for real-time game rendering from olden times. We don't need to use them. Normal mapping from normal maps does not give you any different results than normal mapping from bump maps, assuming both are done correctly. But that assumption is rarely valid.

Poser doesn't use normal maps correctly. Poser does use bump maps correctly. As a consequence, no matter how you make your normal map (there are "right" ways and wrong ways), the result will come out different. It should not be different.

Bump maps are normal maps without the pre-baked math - the renderer does the math on each render, which takes a few dozen extra milliseconds than the normal map. But the bump map comes out right and the normal map does not. This is because the pre-baked math is not fully agreed upon by every 3D program.

Half the 3D programs use normal maps differently than the other half. All of them produce their normal maps from bump maps.

Therefore the only logical thing to do is just use bump maps."