Sony FE 70-200mm F2.8 GM OSS II Lens

Premium G Master Series telephoto zoom lens
Sony Nano AR Coating to eliminate flare and ghosting
Circular 11-blade aperture for beautiful defocus effects
Built-in Optical SteadyShot image stabilization
Dust and moisture-resistant design
An incomparable constant aperture F2.8 70-200 mm telephoto zoom with extraordinary G Master resolution that offers unsurpassed rendering and bokeh, blazing AF, and extraordinary image stabilization performance.G Master design combines extraordinary sharpness and smooth Bokeh in one lens. It is not easy to achieve spatial frequency of 50 lines pairs per millimeter at a lens's widest aperture and produce smooth beautiful bokeh at the same time, but that is Sony's baseline for G Master design. Unprecedented resolution and other demanding design parameters yield outstanding reproduction of the most detailed subjects and scenes with superior contrast throughout every frame. G Master resolution is simply the highest in its class.
Constant F2.8 max aperture maintains exposure and depth of field regardless of the focal range you choose to zoom to. When changing your aperture to defocus the background, the areas out of the focal plane appear blurred. This 'bokeh' effect of the blurred background can be enhanced with circular aperture blades used in this lens.