Outstanding Close-up PerformanceThe lens is provided with excellent close-up performance,which makes it easier to take close-up photos.Lens Construction--10 Elements in 9 GroupsThe lens elements consist of 1 Ed (Extra-low Dispersion) glass and 1 high refractive glass to suppress the distortion.At Fl.4 the depth of field is very small and starts to get blurred from the surrounding F 1.8 of the focal point.Compact and Portable290g lightweight design to meet the various needs of photographers or filmmakersFl.4 Large Aperture Killer Portrait LensThere is a natural transition from the sharp inside focus to the soft out of focus, which contributes the outstanding blur effect. It also features super color rendition.usb Firmware UPGRADEEasy Update Firmware to Experience Better Performance the bottom of the lens is equipped with a micro Usb interface, which is convenient for future firmware upgrades,enabling its more functional performance.