I then project the image onto a poly plane that has been subdivided to a poly count of 1.5 mil. I then zoom out and use the layer brush with a value of 12 which sculpts out the terrain. I will now use this as a reference to sculpt out the terrain so it roughly matches my ref images. I will have to wait an hour before I can begin sculpting though as my wacom is at work but will post and update later today.