The Apo-Symmar-"L" series replace the established original Apo-Symmar line. These lenses are quite similar to their predecessors, but with more environmentally-sensitive glasses in their construction.
They've also inched up the already-outstanding covering power of these lenses a degree or two, to enable more axis displacement for creative control.
When used with the maximum film format allowed by the coverage, the Apo-Symmar series produces a pleasantly normal-looking perspective.