The Leica DG Vario-Summilux 25-50mm f/1.7 ASPH., from Panasonic, is a 50-100mm-equivalent zoom for Micro Four Thirds mirrorless cameras. Normal-to-short-tele zoom is designed for Micro Four Thirds mirrorless cameras and offers a 50-100mm equivalent focal length range. One aspherical element, three extra-low dispersion elements, and one ultra-high-refractive index element all combine to produce well-controlled imagery void of color fringing, chromatic aberrations, and spherical aberrations. The Focus Clutch mechanism allows for intuitive switching between AF and MF modes, simply by sliding the focusing ring, and if paired with select Lumix cameras, Focus Ring Control can be used to tune the focus rotation feeling. The physical aperture ring has a stepless, de-clicked design for smooth, silent aperture switching to benefit video applications. Designed to closely match the Leica DG Vario-Summilux 10-25mm f/1.7 ASPH. lens, these two zooms are nearly identical in terms of form factor and weight, share the same 77mm filter ring diameter, and have a unified color rendering for seamless switching between the two lenses.