1. Open F value 2.8, high performance; (star) lens.We have developed the "Star" series of lenses to compensate for optimal image quality, and compensate for maximum aberration and clarity from the center to the peripheral. When mounted on our K-series digital SLR cameras, it is approximately 2.9x telephoto zoom lens with an approximate 107-307mm focal length in 35mm format. With an open F value of 2.8 in the entire zoom range, it is ideal for portraits and sports shooting where the large aperture lens takes advantage of the background bokeh, and the high-speed shutter stops movement. Furthermore, the image circle is designed to cover up to 35mm film SLR cameras, so when you install it on our current DSLR camera you can enjoy sharp, high-resolution images up to four corners of the screen, and it can also be used for future large-scale image elements.2. Using the latest optical technologyThe ultra-low refractive membrane forming process uses the proprietary new Aero Bright Coating II that achieves superior low reflection properties exceeding the traditional "Aero Bright Coating" note 1". In addition, when used with a high-performance multi-coating "HD Coating Note 2" which reduces the average reflectivity of the visible light range by about 50% or less compared to previous models, it effectively reduces ghosting and flare in harsh shooting conditions such as backlight. In addition, we use 4 unusual low-dispersion glass, 2 special low-dispersion (ED) glass and 2 Super ED glass with low dispersion optical properties similar to fluorite and excellent chromatic aberration correction performance for superior chromatic aberration correction across the zoom range, providing clear and contrast from center to peripheral areas.Note 1: Our proprietary lens coating technology is created from nanotechnology, which is based on silica aerogel with uniform air gaps, providing excellent anti-reflection effect with a wide wavelength range and obtaining high standards of clear images.Note 2: "HD" stands for High Definition.3. Dust-proof, splash-proof construction.The "AW" (All Weather) type has been sealed in 13 places throughout the entire lens as a dustproof and splash-proof structure that prevents water and dust from entering the lens. Combined with our DSLR's dustproof and splash-proof construction, it provides increased durability and reliability in rainy weather, fog, and splashing areas.4. New Quick Shift Focus System SwitchIn order to increase the convenience of the "Quick-shift Focus System" that allows you to manually focus without switching between auto focus and manual focus, we have updated three switches: QFS/A, QFS/M, and MF. Autofocus-priority QFS/A mode allows manual focusing after autofocus is completed, and in QFS/M mode with manual focus priority, you can instantly manually focus even during autofocus operation, and in MF mode you can quickly switch to MF on lens side for smoother and more precise focusing.5. Other1. Motor drive AF in lens provides quiet and smooth autofocus drivingUses a 2-point light source that suppresses the light and provides a soft bokeh effect.3. Equipped with a 3-stage "focus range limiter" that can limit focus range and shorten AF time.4. Stain-resistant SP (Super Protect) coating on the front of the lens.5. Equipped with a removable tripod with a newly developed anti-fall mechanism.