Here is my model of the stormtrooper helmet. As usual, the zip file contains a .obj, .dae, .fbx, and of course a .blend.
OBJ (OBJ, filesize: 14.8 MB), BLEND (Blender, filesize: 14.8 MB), DAE (Collada, filesize: 14.8 MB), FBX (Autodesk FBX, filesize: 14.8 MB)