Sigma 18-35mm f/1.8 Art DC HSM Zoom Lens (for Sony Alpha A-Mount)
The first and fastest of its kind.
Truly a revolutionary product, the Sigma 18-35mm f/1.8 Art DC HSM Zoom Lens (for Sony Alpha A-Mount Cameras) 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 f/1.8 translates to 27-52.5mm on 35mm camera. Tapping into Sigma's long history of lens innovations, it 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 landscape photography, portrait photography, still life photography, snapshots, casual photography, and close-ups. The Hyper Sonic Motor (HSM) ensures smooth, fast and accurate autofocusing. The use of Thermally Composite Material (TSC) reduces size and weight but increases accuracy of the lens construction. Its Global Vision design works features compatibility with the Sigma USB dock for further customization. A 9-blade rounded diaphragm also creates beautiful background blur. The Sigma 18-35mm f/1.8 DC HSM is a new benchmark in photographic history and a must have for every camera bag.
Art line delivers high-level artistic quality:
Sigma is organizing all its interchangeable lenses into three product lines; Contemporary, Art and Sports. Designed with a focus on sophisticated optical performance and abundant expressive power, Sigma's Art line delivers high-level artistic expression. Developed with the maximum emphasis on artistic touch, they are designed to meet the expectations of users who value a creative, dramatic outcome above compactness and multifunction. Along with landscapes, portraits, still-life, close-up and casual snaps, they are perfect for the kind of photography that unleashes the inner artist. Ideal for studio photography, they offer just as much expressive scope when capturing architecture, starry skies, underwater shots and many other scenes.
A zoom lens is very convenient as it offers various angles of view just by rotating the zoom ring. However, the down side was that no zoom lens ever offered a faster aperture than f/2.8 which led photographers to select fixed focal length lenses for brighter images. While the aperture value of prime lenses is superior to zoom lenses, their field of view is always the same, and therefore it was always necessary to carry many fixed focal length lenses. The Sigma 18-35mm f/1.8 DC HSM is a new generation lens that can deliver images at f/1.8 aperture throughout its focal length. The bright viewfinder is very helpful for checking the focus and composition of the image. If it is compared with a lens of f/2.8, the faster shutter speed and the shallow depth of field of f/1.8 further expands creativity. From wide to standard range this lens offers the excellent versatility and performance of multiple fixed focal length lenses.
Cutting edge technology:
To achieve a wide zoom lens with a maximum aperture of f/1.8, various technical problems need to be overcome. As the aperture value gets larger, the depth of focus becomes shallower, thus it makes the lens design extremely complicated in order to compensate for various distortions, such as spherical, axial chromatic and astigmatic aberration along with curvature of field. In order to compensate for astigmatic aberration across the entire focal range, Sigma has relied on the experience and know how gained when designing super wide angle zoom lenses such as the Sigma 12-24mm f/4.5-5.6 II DG HSM and Sigma 8-16mm f/4.5-5.6 DC HSM. In addition, the technological innovation at Sigma's Aizu factory also contributes to better lens production. It has enabled Sigma to develop a wide glass-molded aspheric lens, and the incorporation of SLD (Special Low Dispersion) glass has optimized power distribution of the optical elements and compensated for various aberrations as well as curvature of field at the widest angle. Thanks to Sigma's knowledge of lens design accumulated over a long period of time plus the latest lens manufacturing techniques, Sigma has finally made the dream of a zoom lens with f/1.8 throughout its entire focal range come true.
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.
Hyper Sonic Motor:
The HSM (Hyper Sonic Motor) ensures a silent, high-speed AF function. It also enables full-time manual focusing capability which allows precise focus adjustment by simply rotating the focus ring.
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 also possible to use a specialty filter, such as a Circular Polarizer, as the front part of the lens does not rotate.
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.
The 9-blade rounded diaphragm incorporated into this lens creates an attractive round bokeh at large-aperture settings.
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.
Sigma's 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.
Compatible with optional USB Dock:
Attaching the lens to an optional USB DOCK (planned to be available in 2013) plugged to your computer and using dedicated software "Sigma Optimization Pro", you can update the lens firmware and adjust parameters such as focus.
Evaluation with Sigma's own MTF measuring system "A1":
Sigma used to measure lens performance with MTF measuring system using conventional sensors. However, they have now developed a proprietary MTF (modulation transfer function) measuring system (A1) using 46-megapixel Foveon direct image sensors. Even previously undetectable high-frequency details are now within the scope of quality control inspections. The Sigma 18-35mm f/1.8 Art DC HSM will be checked using this "A1" before they are shipped.
Made in Japan:
All Sigma's manufacturing -- right down to molds and parts -- with a few exceptions, are carried out under a single integrated production system, entirely in Japan. Sigma is now one of the very few manufacturers whose products are solely "made in Japan".