The diameter of the Beseler lens is almost exactly the same, but it's longer in size, at least by 45mm. Which type of Cooke triplet is preferable, from your experience, for the same focal length? A longer or shorter one in length (barrel)? Where does the nodal point lie for a longer-sized lens? Could one simply insert an aperture, cut from a black piece of cardboard, inside, right in front of the middle element?