Sony's FE PZ 28-135mm f/4 G OSS Lens is an advanced powered zoom lens designed for 35mm full-frame format cameras. Created to satisfy professional standards of moviemaking requirements, this lens offers high resolution HD and 4K formats. The lens features a powered zoom control with a variable speed and zoom rotation direction reversal capability. Powering the zoom function is an SSM (Super Sonic wave Motor) drive that allows precise and virtually silent operation. Focus noise is also minimized through weight reduction of the focus element group and use of a linear motor. Iris function is also designed to be smooth and silent for cinematography demands. This lens features an optical design and control technology inherited from Sony’s professional camcorders that ensure no breathing.

Constant F4 Circular Aperture

Constant F4 max aperture maintains exposure and depth of field regardless of the focal range you chose 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. Conventional aperture blades have flat sides creating unappealing polygonal shaped defocused points of light. The Alpha lens overcomes this problem through a unique design that keeps the aperture almost perfectly circular from its wide-open setting to when it is closed by 2 stops. Smoother, more natural defocusing can be obtained as a result

ED Glass / Super ED Glass

As focal lengths get longer, lenses built with conventional optical glass have difficulties with chromatic aberration, and as a result images suffer from lower contrast, lower color quality, and lower resolution. ED glass dramatically reduces chromatic aberration at telephoto ranges, and provides superior contrast across the entire image, even at large aperture settings. The Super ED glass provides enhanced compensation for chromatic aberration.

Aspherical Lens Elements

Aspherical lens design dramatically reduces spherical aberration while also reducing lens size and weight. Spherical aberration is a slight misalignment of the light rays projected on the image plane. This is caused by differences in refraction at different points on conventional spherical lenses which degrade image quality in large-aperture lenses. Specially shaped aspherical elements near the diaphragm restore alignment of light rays at the image plane, maintaining high sharpness and contrast even at maximum aperture and can also be used at other points in the optical path to reduce distortion. Well-designed aspherical elements can reduce the total number of elements required in the lens, thus reducing overall size and weight

HD and 4K Moviemaking

The SELP28135G is a powered zoom lens that has been created to satisfy professional optical and operational requirements for both high-quality stills and movie imagery, including 4K, when matched with a full-frame format camera such as the α7S or a Super 35 format camcorder such as the PXW-FS7.

Super Sonic Wave Motor (SSM)

Sony's Silent Wave Motor technology provides rapid auto-focusing while remaining exceedingly quiet and accurate. The motor produces high torque at slow rotation, and provides immediate start and stop responses. Traveling Waves are transformed into a rotational energy that focuses the optics.