Calhoun Rapid Perspective 14X17 F8 22" 580mm ULF lens covers 16X20 Bausch Lomb
"Antique" brass lens. Probably circa 1910 B&L Rapid Rectilinear style lens, made for an in house brand.
~22" focal length.
Built in diaphragm works nicely, with F stops marked from F8 - 64.
MASSIVE coverage, more than 16X20.
Over all nice shape with all around nice patina, generally clean glass.
Includes original flange.