Zooming in on 2 New Sigma Lenses

Sigma has announced two new zoom lenses and a USB dock for updating the lens firmware and adjusting parameters via new software. The 17-70mm f/2.8-4.0 DC MACRO HSM / OS HSM is a standard DSLR zoom from Sigma’s Contemporary line. A great general-purpose lens, it covers a focal length range of 17-70mm, or 25.5-105mm in 35mm format—meaning it works for everything from wide-angle to medium telephoto shots. The 120-300mm f/2.8 DG OS HSM, from Sigma’s Sports line, is a 35mm lens with a focal length of 120-300mm, covering medium- to long-telephoto—nearly to super-telephoto. Both lenses have fast maximum apertures of f/2.8 for capturing clear shots in low-light situations and using fast shutter speeds to minimize blur caused by subject movement.

The 17-70mm f/2.8-4.0 DC MACRO lens comes in five versions, compatible with the following AF mounts on cameras: Sigma, Sony (D), Nikon (D), Canon and Pentax. The Sigma, Nikon and Canon versions have Sigma’s Optical Stabilizer (OS), while the Sony and Pentax versions do not.

The OS is an image stabilization system that compensates for camera shake. OS offers effective correction of about 4 stops, enabling stabilization even in macro-range photography, where a small blur can be easily identified. For a large-aperture lens, it’s quite compact at a mere 3.1 x 3.2” (79 x 82mm) and 1.03 lb (0.46 kg), without compromising optical performance. By incorporating a smaller OS unit and optimizing the structure and power distribution of the optical elements, Sigma succeeded in making the lens barrel more compact, so that the lens is 30% smaller than their conventional models. They introduced the new compound material TSC (Thermally Stable Composite) into the barrel for greater durability and more compact zoom and scale rings. Also improving durability is the brass-made bayonet mount.

The 17-70mm lens has a minimum focusing distance of 8.7” (22 cm) and a maximum magnification ratio of 1:2.8. At the maximum focal length of 70mm, the effective distance becomes only 2.17” (5.52 cm), meaning the lens can capture images at telephoto focal lengths that are comparable to those shot with a macro lens.

Two FLD (“F” Low Dispersion) glass elements, offering a performance equivalent to that of fluorite, 1 SLD (Special Low Dispersion) glass element, and 3 aspherical glass lenses, including  a double-sided aspherical lens, are contained within the 17-70mm. By optimizing the power alignment of the lens, both chromatic aberration of magnification and axial chromatic aberration have been corrected. From infinity to macro on the focus scale, the lens provides superior image quality throughout the zoom range. The Super Multi-Layer Coating minimizes flare and ghosting and provides sharp, high-contrast images, even in backlit conditions. Use the bright viewfinder to aid in focusing and image composition. 

The lens has 7 rounded diaphragm blades for smooth bokeh in the out-of-focus areas of the image. The Hyper Sonic Motor (HSM) ensures fast, quiet autofocusing, as well as full-time manual focus override via rotation of the focus ring. The AF algorithm has been improved to allow for smoother autofocus.

To maximize ease of use, the design of the lens cap and AF / MF changeover switch has been improved. A petal type Lens hood (LH780-03) is supplied with the lens.

Sigma has developed special software known as SIGMA Optimization Pro, which can update the lens firmware and adjust parameters like focus via the optional USB dock.

The 120-300mm f/2.8 DG OS HSM lens was designed especially for sports, theatrical shows, nature (especially capturing birds and other quick-moving animals) and moving-vehicle photography, as well as other applications where shooting positions are almost always fixed, and changing lenses could mean missed photographs. Thus, this zoom lens was made so that you would not have to swap long-telephoto prime lenses, enabling you to capture all the shots you want during fast action sequences. Sigma’s OS system compensates for camera shake, enabling the use of shutter speeds approximately 4 stops slower than would otherwise be possible. OS mode 1 is best-suited to general photography, and OS mode 2 is optimized for panning shots of subjects, such as planes or racing cars. You can switch the OS mode via the optional USB dock.

The lens is available in three versions, for the following AF mounts on cameras:  Sigma, Nikon (D)  and Canon. The lens is not compatible with film SLR cameras, except for the Nikon F6 and Canon EOS-1v.

With the SIGMA Optimization Pro software provided, usable via the optional USB dock, all sorts of settings can be tailored to your personal preferences. Update the lens firmware and adjust parameters like focus. You can customize AF speed, focus limiter and OS function.

The lens incorporates 2 FLD (“F” Low Dispersion) glass elements with performance equal to Fluorite, in addition to a single SLD (Special Low Dispersion) glass element. These help compensate for color aberration and sagittal coma flare, while reducing the blurring of a point light source in peripheral areas. The lens elements enable the 120-300mm to provide an image quality close to that of a prime lens. Sigma’s Super Multi-Layer Coating reduces flare and ghosting, offering sharp, high-contrast images throughout the zoom range.

An inner focusing and zooming system requires no change in the length of the lens for either focus or zoom.  You can use a rounded filter, such as a Circular Polarizer, as the front part of the lens is fixed. The focus limiter offers an adjustable AF range, and the USB dock lets you alter this range at your discretion.

The lens’s diaphragm comprises 9 rounded blades that create attractive bokeh in out-of-focus regions of the image. The Hyper Sonic Motor (HSM) provides fast, quiet autofocusing and full-time manual focus override by rotation of the focus ring. The enhanced AF algorithm enables smoother AF, while the full time manual permits further adjustments after focusing with AF mode. The USB dock lets you change and adjust the AF speed as you wish.

The lens’s joint parts, including the mount attachment, manual ring, zoom-ring, switches for customization and external switch panels, have been made dust proof and splash proof to help prevent damage to the lens.  Another attribute that adds to the lens’s durability is the brass bayonet mount.

A lens case, removable lens hood (LH1220-01), shoulder strap and tripod collar (TS-51) are supplied. Two APO Tele-Converters for extending the lens’s focal length well into the super-telephoto range are optional: the 1.4x EX DG APO turns the lens into a 168-420mm f/4, while the 2x EX DG APO makes it a 240-600mm f/5.6.

Sigma has evaluated both lenses with its own MTF measuring system, “A1,” which utilizes 46-MP Foveon direct image sensors rather than conventional sensors. High-frequency details that were previously undetectable are now within the scope of inspection.

Both lenses, like all Sigma products, are manufactured in Japan.