Leica DG Vario-Summilux 10-25mm f/1.7 ASPH. from Panasonic

LEICA DG VARIO-SUMMILUX 10-25mm / F1.7 ASPH. H-X1025 is built for mirrorless Micro Four Thirds mount cameras and enables F1.7 aperture brightness throughout the entire 20-50mm (35mm camera equivalent) zoom range with exceptionally high optical performance clearing the stringent LEICA standards. Suitable not only for photo shooting but also for video recording to satisfy both professional photographers and videographers.Comprising 17 elements in 12 groups, the lens system features three aspherical lenses and four ED (Extra-low Dispersion) lenses that effectively suppress the axial chromatic aberration and chromatic aberration of magnification. Spherical aberration and distortion are also corrected by the aspherical lenses for stunningly high resolution. The use of aspherical lenses and the optimum design of the lens system results in a compact size and light weight despite its outstanding optical performance.Compatibility with a maximum 240-fps high-speed sensor drive realizes high-speed, high-precision autofocusing. Notably, the new lens excels in video recording performance. In addition to the silent operation achieved by the inner focus drive system, the stepless “de-cliked” aperture ring and micro-step drive system in the aperture control section help the camera to smoothly catch up to brightness changes when zooming or panning. The optical design achieves exceptional barycentric stability to minimize image shifts during zooming. Adoption of a focus clutch mechanism enables instant AF/MF switching and accurate manual focusing. The lens also excels in video recording performance with a mechanism that suppresses focus breathing, which was a fatal problem of all interchangeable lenses designed for still image photography.