A new specification, 47.25" x 31.5" (1200mm x 800mm) Subject Framing Distance, has been added to the Lens Specifications and Measurements Tool.
This is the laser measured distance from the camera sensor plane to a subject framed the specified size at the specified focal length. Use these values to compare lenses or to determine if a lens will meet your needs. Most Canon and Nikon lenses and many other third party lenses have this information included in the database.