Reported by Mat Gallagher:
It seems Sigma is pushing the boundaries of lens design once again with the introduction of this rather impressive optic. The 18-35mm f/1.8 DC HSM is designed to cover APS-C sensors and is perhaps rather a short range, compared to a standard 18-55mm kit lens. However, it does still cover the full-frame equivalent of 27-52.5mm, giving you the often used 28mm, 35mm, and 50mm focal lengths. The most interesting this about this lens though, is its aperture. The f/1.8 is constant through the zoom and is
two stops (Edit – it’s one and a third stops) brighter than what would normally be offered by a standard zoom, giving it a distinct advantage for low light and shallow depth-of-field work. This is, of course, a high-end lens with a complex construction of 17 elements in 12 groups, and at over 12cm long it’s hardly compact. It features Sigma’s HSM focusing for quiet and fast operation. All focus and zoom is internal, and the front element does not rotate, making it suitable for attaching larger filters and polarisers. The lens is expected to be available in Canon, Nikon and Sigma mounts. For those using APS-C cameras for video this is bound to be a tempting proposition, and I’m sure Sony NEX and Fuji X-Pro users will be hoping it extends into their mounts, too. Price and availability are still to be confirmed. (Site editors note: From the photos the focus throw of this lens does seem to be very short, just like other most other AF zooms – not so great for video)
From the manufacturer:
RONKONKOMA, NY — Sigma Corporation of America (www.sigmaphoto.com), a leading researcher, developer, manufacturer and service provider for some of the world’s most impressive lines of lenses, cameras and flashes, today announced the Sigma 18-35mm F1.8 DC HSM Art lens, the market’s first zoom lens to achieve a maximum aperture F1.8 throughout the entire zoom range.
This revolutionary, wide aperture, standard zoom lens is created for DSLR cameras with APS-C size sensors, which translates to a focal range of 27-52.5mm on a 35mm camera. With a minimum focusing distance of 11 inches, and a maximum magnification ratio of 1:4.3, the 18-35mm is ideal for landscapes, portraits, still-life, studio, close-up and casual photography.
“Exceptionally fast apertures were previously unavailable in zoom lenses, so photographers turned to several prime lenses in a session to get bright images at various focal lengths. We’re incredibly excited to be the first manufacturer to bring the F1.8 standard zoom to the market and to provide photographers with a new level of creativity and convenience, with the outstanding image quality at the core of the new Sigma Global Vision,” said Mark Amir-Hamzeh, president of Sigma Corporation of America.
Amir-Hamzeh added that because developing a large aperture wide angle zoom lens can prove to be technologically and optically challenging, often resulting in various distortions, aberrations and field curvature, Sigma has tapped into its long history as a lens pioneer to overcome those issues in this new generation lens.
“Our experience with the wide angle designs of our 12-24mm F4.5-5.6 II DG HSM and our 8-16mm F4.5-5.6 DC HSM, and our research and development in our Aizu factory have prepared us for this technological advancement,” he said. “Our wide, glass-molded aspherical lens and the incorporation of Special Low Dispersion (SLD) glass have optimized power distribution of the optical elements and compensated for various aberrations, as well as curvature of field at the widest angle. We’re extremely proud of this achievement.”
The 18-35mm is the latest addition to the company’s Art line of lenses, designed under the new Global Vision. The Global Vision lenses have a sleek new design with the manufacturing year stamped on the barrel, and are categorized by use into one of three groups: Art, Contemporary and Sports. The Art category delivers high-level artistic expression through sophisticated and abundant expressive power.
The new 18-35mm lens incorporates Sigma’s improved AF/MF switch and the use of Thermally Stable Composite (TSC) compound material, which has a high affinity to metal parts, consistently performs well at extreme temperatures, and reduces the size and weight of the lens. It is also compatible with Sigma’s new USB Dock, which will be available in coming months, enabling photographers to update lens firmware and adjust focus parameters from their computers.
Convenient handling is achieved with internal focusing and zooming, which prevents changes to the size of the lens. Additionally, the front part of the lens does not rotate, so special filters like circular polarizers can be used.
The 18-35mm lens’ Super Multi-Layer Coating reduces flare and ghosting and provides sharp and high contrast images, even in backlit conditions. The petal-type hood that is supplied with the lens will provide extra protection from flare and ghosting. Sigma’s Hyper Sonic Motor (HSM) ensures a silent, high-speed AF function and the optimized auto focus algorithm results in smooth focusing and full-time manual focusing capability. Lastly, the nine-blade, rounded diaphragm creates an attractive, round bokeh at large-aperture settings.
Lens Construction: 17 elements in 12 groups
Minimum aperture f16
Filter size: 72mm
Angle of view (SD1): 76.5°-44.2°
Minimum focusing distance: 11in
Dimensions (Diameter x Length): 3.1 inches x 4.8 inches
Number of diaphragm blades: 9 (rounded diaphragm)
Maximum magnification ratio: 1:4.3
Weight: 28.6 oz