Creating Normal maps From A Photo

A week or two ago I was looking at a BlenderGuru video that mentioned CrazyBump as a tool for creating a variety of maps from a texture image. But that's $99.
While searching for more information I found this https://blenderlex.wordpress.com/2015/03/12/installing-insane-bump-for-gimp-windows/ which led me to these GIMP plugins:

normalmap - http://registry.gimp.org/node/69   (haven't tried this)
Insane Bump (Python) - http://registry.gimp.org/node/28117    (tried it but it needs normalmap?)
Insane Bump (C) - http://registry.gimp.org/node/28638  (with the DLL in the same folder this works)

My first play with it (the C version) worked nicely. Here's thumbs of the maps created from one of my photos:



 
Here's a Poser 9 render using these maps together:

Here's the shader I used:

And here's what the render was like with just the texture:

I did some checks and confirmed that the normal maps created by the plugin are correctly oriented for Poser. They're tangent space, with green being down-up (0 is down, 1 is up) and red left-right (0 is left, 1 is right) when viewing the normal map in GIMP. That makes sense to me even if it doesn't to you!  ;o)