Hello All, I purchased this wonderful little lens today and would like to learn more about it. On the brass rim it says- The Scientific Lens Co. Extr W.A. Anastigmat No.5 With front and rear glass in place it measures about a 8-9 inch focal length and with either the rear or front element removed it has an amazing 22 inch focal length. How can I tell what size film the lens will cover? I assume that if it is an extra W.A. lens and the focal length is 8-9 inches it is made for at least an 8x10 camera? Any info would be a great help.