Normal Map Sampling / Influence Question


I have a question regarding Normal Maps…
(I’m using Blender Render and am on v.2.73)

I understand how to bring in the Normal Map as a second texture to a material. I then seem to have several options what to do with it.

To make it take effect, I need to tick the box “Normal” in Geometry under the Influence Header. (And turn off the standard selected “Colour” in Diffuse).

With this alone I can see some effect in the 3D view in Edit mode. It works from any angle. It’s very detailed but very flat, as if vacuumed to the mesh underneath.

And then I also have the option to tick the box “Normal Map” under the Image Sampling Header. This will also have some apparent effect in the texture, but it looks greatly different. It seems less detailed, but it has greater volume and resembles more the actual texture underneath - basically that’s what I expect the Normal to do.
But in Edit mode, I can see this effect only from certain angles to the light source! If a cube was so positioned that two faces get equal light … I can still only see the Normal Map effect on one face when rotating around the cube while the other is completely flat. And yet, when going back to Object Mode, the whole object is affected, as expected.

So why does this change happen between Edit and Object Mode …
And just what is that effect of the Normal Map without the Normal Map Sampling activated? Which one is the one people normally want when working with Normal Maps?
And is that the correct application of Normal Maps at all? What else might need to be ticked or altered to display a Normal Map as intended?

Many thanks for any help. :smiley: