Leveraging major manufacturing advances at the Aizu factory, SIGMA is now producing ultra-high-precision molded glass aspherical lens elements as large as φ80mm and incorporating them in new products. This premier optical technology promises to set a new standard for excellence in ultra-wide-angle lenses.
For the Art line, SIGMA began development simultaneously of two ultra-wide-angle lenses offering the key focal length of 14mm: one prime, and one zoom. In 2017, the company launched the 14mm F1.8 DG HSM | Art as the ultimate ultra-wide-angle prime lens. This lens offers outstanding image quality in combination with F1.8 brightness.
Now SIGMA is introducing the 14-24mm F2.8 DG HSM | Art as the ultimate ultra-wide-angle zoom. While minimizing distortion, this lens offers outstanding F2.8 brightness throughout the zoom range and delivers top-level image quality at every focal length and every shooting distance. For these reasons, it is the definitive large-diameter ultra-wide-angle zoom lens.
Designed to team up with 50-megapixel-plus cameras and offer top-level optical performance throughout the zoom range, the 14-24mm F2.8 DG HSM | Art incorporates three FLD glass elements, three SLD glass elements, and three aspherical lens elements, including one large-diameter aspherical element. Effective distribution of these high-refractive-index glass elements further enhances the corrective effect of the FLD and SLD glass. This optical system minimizes transverse chromatic aberration and other optical aberrations, resulting in outstanding high-resolution image quality.
The first element in the optical system is a large-diameter aspherical lens. Optimizing the power distribution of this and the other lens elements minimizes distortion to 1% or lower.* As a result, points of light appear as points without streaking from the center of the image to the edge, and the light volume is also abundant throughout the frame. In addition, simulations performed from the design stage onward have helped minimize flare and ghosting. In combination, these technologies ensure excellent ultra-wide-angle performance.
* At infinity focus
The degree to which light is refracted by glass depends on the light's wavelength. This fact causes different colors of light to focus at slightly different points. The result is chromatic aberration, the color fringing that is particularly noticeable in telephoto lenses. Most chromatic aberration can be removed by combining a high-refractivity convex lens element with a low-refractivity concave element. Yet residual chromatic aberration known as “secondary spectrum” may still remain. To minimize this secondary spectrum, which can be a serious issue with conventional lenses, SIGMA lenses feature up to three types of exclusive low-dispersion glass offering superior performance: ELD (Extraordinary Low Dispersion), SLD (Special Low Dispersion) and FLD (“F” Low Dispersion). In particular, FLD glass offers ultra-low dispersion in combination with high transmittance and the anomalous dispersion characteristics of fluorite. Meticulous deployment of these types of exclusive low-dispersion glass and optimization of power distribution gives SIGMA lenses superlative image rendition undiminished by residual chromatic aberration.
From an early stage in the lens design process, flare and ghosting have been measured to establish an optical design resistant to strong incident light sources such as backlighting. SIGMA’s Super Multi-Layer Coating reduces flare and ghosting to help photographers produce sharp and high contrast images even in backlit conditions. The included lens hood can be attached to block out extraneous light, which can have a negative effect on rendering performance.
Like SIGMA’s Sports line lenses, the 14-24mm F2.8 DG HSM | Art features a highly effective dust- and splash-proof structure with special sealing at the mount connection, manual focus ring, zoom ring, and cover connection, allowing photographers to work in all types of weather. In addition, the front of the lens is protected by a water- and oil-repellent coating that makes cleaning easy. The high-speed, high-accuracy autofocus helps photographers react in an instant to get those special shots.
Full-time manual focus function allows the lens to be switched to manual focus simply by rotating the focus ring.
Note: The operation of full-time MF may vary based on mount type.
The brass mount combines high precision with rugged construction. Its treated surfaces and enhanced strength contribute to the exceptional durability of the lens.
The 9-blade rounded diaphragm creates an attractive blur in the out-of-focus areas of the image.
For more information head over to the Sigma website