Sigma's New 17-70mm "Floating Iris" Lens.
Sigma has released the 17-70mm T2.8-4. They are calling it the â€œUltimate Standard Lensâ€. I would beg to differ. There is nothing ultimate about the lens changing aperture cause of a little zoom action. Â The iris change makes this more like a T4 lens than a T2.8. Another limiting factor is that this is a DC or APS-C lens that does not cover full frame 35mm.
This lens does have some decent focus markings and image stabilization. A close focus of 8.7 inches throughout the entire zoom range and an inner focus system. Yet the iris changes. This makes the lens almost useless for video. When are lens companies going to figure out that we want to be able to lock in exposure at any focal range? Not screw around with ISO in the middle of the shot.
Press Release Here.
â€˜Ultimate standard lensâ€™ now available in Canon, Nikon, Pentax, Sony and Sigma mounts
Sigma Corporation, a leading researcher, developer, manufacturer and service provider of some of the worldâ€™s most impressive lines of lenses, cameras and flashes, is pleased to announce its newly upgraded 17-70mm F2.8-4 DC Macro OS HSM lens.
This large aperture, standard zoom lens contains state-of-the-art enhancements, including the companyâ€™s own Optical Stabilization (OS), anti-shake technology that offers the use of shutter speeds approximately four stops slower than would otherwise be possible. Once again, only Sigma has made it possible for Pentax and Sony shooters to utilize an anti-shake system in either the lens or the camera body.
This lensâ€™ predecessor, the 17-70mm F2.8-4.5 DC Macro HSM, was deemed a â€œBest Buyâ€ recommendation for photographers wishing to purchase a standard zoom lens as part of the Canadian Association for Photographic Artâ€™s (CAPA) â€œBest Lens of the Yearâ€ awards.
â€œAside from the OS technology, which is key when shooting with mid-range and high-end class DSLRs, this lens stands apart from the crowd because of its impressive zoom range,â€ said Mark Amir-Hamzeh, general manager of Sigma Corporation of America. â€œIt has a 4x zoom range that is equivalent to 24-105mm lenses in full-frame formats. That, coupled with the OS technology and a macro function, makes it the ultimate standard lens for serious photographers who want top-notch image quality and functionality at an affordable price.â€
With a large aperture of F2.8 on the wide end and F4 at the tele end, as well as a macro function with a minimum focusing distance of 8.7 inches and a maximum magnification ratio of 1:2.7, this lens is ideal for a wide range of photography. The lensâ€™ Hyper Sonic Motor (HSM) also ensures a quiet and high speed auto focus, while its rounded, seven-blade diaphragm creates an attractive blur to the out-of-focus areas to provide the optimal Bokeh effect. The inner focusing system eliminates front lens rotation, making the lens particularly suitable for using the supplied petal-type lens hood and circular polarizing filters.
Three aspherical lenses and one Extraordinary Low Dispersion (ELD) glass element provide excellent correction for all types of aberrations when shooting with this lens. Additionally, the Super Multi-Layer Coating reduces flare and ghosting to produce high-contrast images.
The 17-70mm F2.8-4 DC Macro OS HSM lens is currently available in Sigma, Canon, Nikon (D), Sony (D) and Pentax mounts forÂ $680 MSRP in stores nationwide.