Sigma quietly introduces constant-aperture, full-frame 24-105mm f/4 zoom lens
posted Monday, October 14, 2013 at 5:24 PM EDT
For its latest lens launch, Sigma has taken an unusually low-key approach: The brand-new Art-series Sigma 24-105mm F4 DG OS HSM itself does the talking, with no formal announcement made alongside its introduction. But don't let that sell it short: It looks like a very interesting lens indeed.
With approximately a 4.4x optical zoom, the new lens has a constant f/4 maximum aperture, and covers everything from a generous wide angle to a moderate telephoto with a full frame 35mm image circle. (Of course, you can use it on a crop sensor camera, too. In that case, you'll find a 35mm-equivalent focal range of 36-158mm on most APS-C bodies, while the slightly stronger crop of Canon bodies will yield a 38-168mm range.) Both optical stabilization and a hypersonic autofocus motor are included in the design, and the lens employs internal focus and zoom mechanisms. The large 82mm threads on the front don't rotate with focus or zoom, either, so you can set your circular polarizing filter once and then adjust both variables without moving the filter.
Sigma says that, as with other Art series models, the 24-105mm F4 DG OS HSM lens has been designed with high image quality as a key goal. A complex formula of 19 elements in 14 groups includes three aspheric, two "F" low dispersion, and two special low dispersion elements, aimed at controlling vignetting, astigmatism, field curvature, distortion, and chromatic aberration. A Super Multi-layer Coating, meanwhile, keeps flare and ghosting in check, as does a bundled lens hood. And Sigma's Thermally Stable Composite material is used in the lens barrel, to keep thermal shrinkage to a minimum. For attractive bokeh, the lens aperture diaphragm has nine rounded blades.
The new lens is compatible with Sigma's USB dock for firmware updates, focus adjustments, and so forth, and will focus as close as 17.7 inches (45cm). It has a maximum magnification ratio of 1:4.6. Dimensions are 3.5 inches (89mm) in diameter, and 4.3 inches (109mm) in length. Weight is 31.2 ounces (885g).
Since there hasn't so far been an official announcement of the lens, we don't yet know Sigma's plans for pricing or availability. We do know, however, that it will be available in Sigma's own mount, as well as in Canon, Nikon, and Sony mounts. More details on the Sigma global website.
(via Nikon Rumors)