US 8,508,864 B2↗2013Assignee: ACM Projektentwicklung GmbHInventors: Iain A. NeilLEICA SUMMILUX-C 100mm T1.4— 13 ELEMENTS / 10 AIR-SPACED GROUPS, 3 FUNCTIONAL GROUPS (G1a / G1b / G2)LEICA SUMMILUX-C 40mm T1.4— 15 ELEMENTS / 11 AIR-SPACED GROUPS, 2 PATENT MACRO-GROUPS (G1 + G2)