F/1.7-2.8 Leica Lens. The 4/3" 12.8MP sensor provides high-resolution output, and with its bright, optically-stabilized DC Vario-Summilux f/1.7-2.8 lens, as well as an ISO range expandable from 100 to 25600, the D-LUX (Typ 109)'s ability to perform under low-light conditions is further enhanced.