Vario-Tessar T* E 16-70mm F4 ZA OSS Lens
The latest advances in optical design technology have made it possible to deliver prized Carl Zeiss contrast and clarity in a high-performance mid-range zoom. Four aspherical elements combine with one ED glass element to bring you breathtaking rendering.
Circular Aperture
When changing your aperture to defocus the background, the light sources 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 defocussed points of light. α lenses overcome 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 (Extra-low Dispersion) 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. Super ED glass provides enhanced compensation for chromatic aberration.