Per Goerz, the 14 inch Artar covers 14 x 17 at 1:1, i.e., 7 x 8.5 at infinity. 7 x 8.5 seems smaller than 8 x 10.
Originally Posted by LJH
Its hard to imagine how the lens was screwed together as the OP reported. Its unusual for individual elements' mounts to be threaded so that assembly as described by the OP reported is possible. I believe him, am puzzled.
The lens isn't fit for its intended purpose and its condition is unknown and suspect until proven otherwise. 16.5"/9.5 Artars aren't rare and will do what the OP needs. They can even be put in shutter..