Hello now I have my 20x24 camera with 2,5 meter bellow and I would like to buy a quite a long lens for portrait in studio. I can either buy an apo ronar or an apo nikkor... I have difficulties to choose as Theese 2 lens are about the same, but If you compare them, they are quite different. The apo Nikkor is much heavier, quiet a bit longer (but is it really different ?) a bit faster (but not much)... Well the apo ronar is cheaper... so, what do you think would be the best choice for what I want to do ? and why ? thank you for your advice, Thierry M.L.