I have now started building a panoramic roll film camera, and am in need of one piece of info. I have a 90mm Rodenstock f6.8 lens, and need to know to what poi nt on the lens (nodal point I think they call it), from the film plane, I need t o measure to give me 90mm, so that the lens will be focussed at infinity.

As I will not have a ground glass, and no bellows, I will be using a solid alumi num cone, I need to have the film plane to the nodal point of the lens as accura te as possible. Do I understand it correctly, that when the lens is focussed at infinity, in this case at 90mm from the film plane,the lens will be in focus. I addition, how does one determine the closest point that will be in focus.

Thanks for your help. Karl Beath