The Leica DG Summilux 9mm F1.7 is for use by professionals and high amateur users for both photo shooting and video recording, capable of smooth, silent operation to work with the camera's high-speed, high-precision contrast AF system with the sensor drive at max.240 fps. For the non-linear setting, focus is shifted with a variable amount according to the rotation speed of the focus ring while focus is shifted with a designated amount according to the rotational quantum of the focus ring for the linear setting. It also excels in video recording performance, with a mechanism that suppresses focus breathing, together with a micro-step aperture control for smooth exposure change.Comprised of twelve lens elements in nine groups including two aspherical lenses, H-X09 has two ED (Extra-Low Dispersion) lenses and one UHR (Ultra High Refractive Index) lens to effectively suppress both axial chromatic aberration and chromatic aberration of magnification.With its approximately 130g compact size and light weight, the Leica DG Summilux 9mm F1.7 features stunning mobility that Micro Four Thirds system boasts. The rugged dust/splash-resistant design withstands use under harsh conditions even at 10 degrees below zero. The filter diameter is 55 mm, with a 7-blade circular aperture diaphragm.f Micro Four Thirds Lens for Professional Photographers and VideographersHigh descriptive performance lens provides smooth, beautiful bokeh in photo and video; works wi