Well the next lens i want to get is a nice fisheye lens. Now theres one thing that i noticed long ago when reading up on them and ive never understood fully.. ok. So focal lengths with lenses. less mm = wider fov. now, i see fisheyes. one says its 10.5mm one says 8mm one says 4.5mm Yet they all say they give a 180 degree fov image. so.. does that mean the 10.5mm fisheye is just as wide as the 4.5mm fisheye? and if so.. why the different numbers?