This compact full-frame Carl Zeiss mid-range zoom lens covers a 24-70mm range with a constant maximum aperture of f/4, enabling consistent exposure settings at any focal length. This premium lens delivers superlative image quality with full-frame and APS-C E-mount cameras, and dust/moisture resistance means consistently reliable performance. A standard zoom lens is a lens in which the focal length varies, unlike a prime or fixed lens. A zoom lens is one that maintain (or regains) focus even with focal length of the subject-matter changes. Zoom lenses, such as this, provide the user with a convenient, go-to lens of variable focal length.

Constant f/4 Aperture

Constant f/4 aperture at all focal lengths means that the user can zoom and shoot at any aperture without having to worry about changes in exposure settings or depth of field, concentrating on the image rather than technical details.

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.

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. Advanced Aspherical (AA) elements are an evolved variant, featuring an extremely high thickness ratio between the center and periphery. AA elements are exceedingly difficult to produce, relying on the most advanced molding technology to consistently and precisely achieve the required shape and surface accuracy, resulting in significantly improved image accuracy and quality.

ZEISS T* Coating

The Zeiss T* coating is an important contributing factor, effectively suppressing spurious reflections that can degrade overall image quality. Flare and ghosting are reduced for enhanced color and contrast that give images a deep, three-dimensional feel.

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. Alpha 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.