Sigma lenses at Photokina
We have had the opportunity to meet Michihiro Yamaki, President of Sigma Corporation. During our meeting we were shown the latest lenses Sigma has announced just before the Photokina started. The new 18-125mm F3.5-5.6 DC for Four Thirds mount is exclusively designed for use with digital Single Lens Reflex (SLR) cameras and has a 1: 6.9 zoom ratio. A Special Low Dispersion (SLD) and two aspherical glass elements produce a top quality optical performance throughout the entire zoom range. The new Super Multi Layer lens coating, which is optimized for digital SLR cameras, gives superb colour rendition whilst cutting down flare and ghost.
Sigma 18-125mm F3.5-5.6 DC lens
This lens has a minimum focusing distance of 50cm at all focal lengths and is equipped with an inner focusing system. As the front of the lens does not rotate, the Petal shaped hood and circular polarizing filters can be easily used. This lens is also equipped with a zoom lock switch that eliminates "Zoom Creep".
Sigma Tele Macro 150mm F2.8 EX DG HSM lens
The second Sigma lens is the world's first High Speed Tele Macro 150mm F2.8 EX DG HSM lens. This large aperture telephoto Macro lens enables you to shoot up to 1:1 life size close-ups. Its large F2.8 aperture makes it an ideal lens for digital SLR as well as film SLR cameras. The new lens power layout provides the ultimate correction against lateral chromatic aberration to which digital cameras are prone. Two Special Low Dispersion (SLD) glass elements control various colour aberrations and assure high image quality. A floating focusing system moves two different lens groups in the optical system to different positions. This system compensates for astigmatic aberration and spherical aberration. The HSM models provide ultra quiet high-speed auto focusing as well as full-time manual focus override.
Sigma 24-70mm F2.8 EX DG Macro lens
The third lens is the 24-70mm F2.8 EX DG Macro lens. From 24mm super wide angle to 70mm medium telephoto, this lens provides a large F2.8 aperture at all focal lengths. This lens incorporates Super Multi Layer Coating to reduce the influence of harmful light caused by reflections from the digital image sensor. Two SLD elements, one Glass Mold Aspherical plus two Hybrid Aspherical lenses provide excellent correction of various aberrations and a high level of optical performance. The lens has a minimum focusing distance of 40cm at all focal lengths and is capable of Macro photography with a maximum magnification ratio of 1:3.8. It also incorporates a Dual Focus (DF) system that is designed to make the lens easy to hold during auto focusing, and yet provides a large focus ring for easy manual focusing. Since the front of the lens does not rotate, a Petal-type hood and circular polarizing filters can be easily used.
Sigma 28-70mm F2.8 EX DG lens
Last, but not least, the new 28-70mm F2.8 EX DG lens. This is the world's smallest, large and constant aperture zoom lens and is ideal for digital SLR cameras. The power layout of the lens is specially optimized for digital SLR cameras, and Super Multi Coating gives superb colour performance whilst cutting down flare and ghost. Two SLD elements and four aspherical lenses provide the ultimate correction against distortion as well as all types of aberration, especially spherical aberration. Its advanced optical design ensures high performance throughout the entire zoom range. The use of aspherical lenses in the construction of this lens not only corrects aberrations but also produces a very small and lightweight lens design. Its compact, yet robust, construction has an overall length of 87.2mm, maximum diameter of 74mm, filter size of 67mm and weight of 510g. It has a minimum focusing distance of 33cm at all focal lengths and a maximum magnification ratio of 1:4.4 which is very convenient for close-up photography. The inner focus system allows the lens to be focused without rotating the front element, therefore a Petal-type hood and circular polarizing filters can easily be used.