First off, thank you for the quick replys.
I don't mean to beat a dead horse but, how can one determine if the 450mm Nikkor M will cover a 12x20 by just looking at the lens? I am sure there is a tech sheet that would come with the lens but when trying to buy one and looking at them the tech sheet is not always available. I did some more research and found that to cover a 12x20 neg I would need a 180 degree coverage at minumum.
Any other thoughts.