Originally Posted by ReallyBigCameras
The 305mm Computar will cover 8x20 with plenty to spare. Unfortunately, it's a lot harder to find and much more expensive then the 305mm G Claron (Quality Camera currently has one listed at $1995.00).
Really Big Cameras
240mm Computar will also cover 7X17, barely, and 270mm Computar will cover with lots of movement. These are great wide angle lenses for the format if size and weight are a major consideration.