A Sigma é a primeira fabricante a oferecer uma lente zoom com abertura de 1.8. - See more at: http://www.fotografia-dg.com/sigma-anuncia-objetiva-18-35mm-f1-8-para-cameras-aps-c/#sthash.THTt032s.dpuf
Distâncias focais: 18 – 35mm
Ângulo de visão: 44.2° – 76.5°
Equivalência em 35mm: 27mm – 52.5mm
Abertura máxima: f/1.8
Abertura mínima: f/16
Tamanho do filtro: 72mm
Foco interno: sim
Distância mínima de foco: 28cm
Elementos: 17 em 12 grupos
Truly a revolutionary product, the Sigma 18-35mm 1.8 DC HSM is the first wide-angle to standard zoom lens to achieve a large aperture of 1.8. Designed specifically for APS-C sized sensors, the Sigma 18-35mm 1.8 translates to 27mm-52.5mm on 35mm camera. Tapping into Sigma’s long history of lens innovations, the 18-35mm 1.8 DC HSM incorporates a wide glass molded aspherical lens with Special Low Dispersion (SLD) glass to compensate for aberrations and curvature at the widest angle. Internal focusing and zooming allows for more usability and functionality. The 18-35mm is ideal for landscapes, portraits, still life, snap shots, casual, and close-ups and the Hyper Sonic Motor (HSM) ensures smooth, fast and accurate autofocusing. The use of Thermally Composite Material (TSC) reduces size and weight but increases the lens durability. Its new Global Vision design works with its compatibility with the Sigma USB dock for further customization. A 9 blade rounded diaphragm also creates beautiful background blur. The Sigma 18-35mm 1.8 DC HSM is a new benchmark in photographic history and a must have for every camera bag.
Convenient handling is achieved by incorporating internal focusing and zooming which prevents any change in the length of the lens when focusing and zooming. It is possible to use a specialist filter, such as a Circular Polarizer, as the front part of the lens does not rotate.
Designed to minimize flare and ghosting
Flare and ghosting were thoroughly measured and monitored from an early stage in the lenses development to establish an optical design which is resistant to strong incidental light such as backlight. The Super Multi-Layer Coating reduces flare and ghosting and provides sharp and high contrast images even in backlit conditions. Attaching the matched petal type hood, which is supplied, will provide extra protection from flare and ghosting.
Minimum focusing distance of 28cm
With a minimum focusing distance of 28cm and a maximum magnification ratio of 1:4.3, this lens is excellent for close-up photography.
Hyper Sonic Motor
Hyper Sonic Motor
The HSM (Hyper Sonic Motor) ensures a silent, high-speed AF function. Optimizing AF algorithm, smoother AF is achieved. It also enables full-time manual focusing capability which allows sensible focus adjustment by simply rotating the focus ring.
Incorporating Rounded diaphragm
The 9 blade rounded diaphragm creates an attractive round bokeh at large-aperture settings.
The new product lines incorporate rubber for the attachment part of the provided lens hood. For better usability, the designs of the lens cap and AF/MF changeover switch have been improved. In order to ensure high accuracy of the product, all metallic parts and the new compound material, TSC (Thermally Stable Composite), which has a high affinity to metal parts, are housed internally. On the lens barrel, the last three digits of its release year are engraved so the lens can be identified according to the year of its launch.
Brass made bayonet mount
This lens incorporates a brass made bayonet mount which has both high accuracy and durability. A special treatment to reinforce its strength is applied to the surface giving it greater strength and making it highly resistant to long-term use.