Enblend is a tool for compositing images. Given a set of images that overlap in some irregular way, Enblend overlays them in such a way that the seam between the images is invisible, or at least very difficult to see. Enblend does not line up the images for you. Use a tool like Hugin to do that.
There may or may not be US patents covering stitching of fisheye photographs, consequently the sourcecode of this library has an artificial limit that prevents the use of fisheye images with a field of view greater than 160°.