I am trying do perform a displacement map in a conical shape. I created a circle, extruded in Z and resized at the other side. After that, I selected everything and subdivided to have a bunch of small faces. Then, I added a displace modifier and a image texture, so that it becomes like the surface in the top (Object Mode):

[![Displacement map without "displaced" normals][1]][1]

The problem is, when I change to Edit Mode I can see that the normals keep as the surface was completely regular, which is not desirabe. I wanted the normals to follow the surface relief, is there a way to do that?

Edit: Accepted answer from Robin Betts, results:
[![enter image description here][2]][2]


  [1]: https://i.sstatic.net/PuZWJ.png
  [2]: https://i.sstatic.net/dN1eA.png