TheDarkShadow

To each their own.. I save as a TGA then convert to BC5 using the nvidia texture tools. I guess I should've worded it differently, this method works for me and I've seen others use it, since nobody else in this topic actually gave a method I thought I'd share it. I wasn't try to bash anybody but in the end the OP and others now have two methods to try instead of one so it's even better.

To edit FO4 normal maps in Photoshop use levels to change the RGB black level from 0 to 128, once that is done you will be able to work on them like regular normal maps. Once you are done you must save them as a DDS with 3Dc compression, you will notice that once saved like that if you open them again they will look faded like the Vanilla textures. For the _S/smooth map you have to edit the RGB channels separately, Red is Specular (black no reflection, white max reflection), Green is Gloss (black matte, white chrome) and Blue seems to be unused on the textures I've tested with even though it has stuff in it.