Sigma Corporation Press Release 20/07/04

EX series, large aperture zoom lens designed specifically for use with digital SLR cameras.

F2.8 large aperture standard zoom lens designed specially for use with digital SLR cameras.
The characteristics of digital SLR cameras were taken into consideration when designing the lens power layout. The new advanced lens design corrects various aberrations. This lens provides the utmost correction against lateral chromatic aberration which is a serious problem for digital SLR cameras.

This lens is specially coated to get the best color balance whilst cutting down flare and ghost caused by reflections from the digital image sensor and lens. It has excellent correction for vignetting and superior peripheral brightness is ensured.

A Special Low Dispersion (SLD) lens and two aspherical lens elements provide excellent correction for all types of aberrations. The design produces a compact and lightweight, yet robust, construction with an overall length of 84.1mm (3.3in.) and maximum diameter of 74.1mm (2.9in.) and weight of 445g (15.7oz).

This lens has a minimum focusing distance of 28cm (11in.). It is equipped with inner focusing system. The non-rotating front lens element makes the lens suitable for using its petal-type lens hood and circular polarizing filters.

It is an ideal large aperture standard zoom lens for digital SLR cameras featuring APS-C size image sensor.

- EX lens series denotes excellence of engineering and new technology.
- Compact and lightweight zoom despite large F2.8 aperture.
- Excellent correction for various types of aberration provided by one SLD (Special Low Dispersion) glass element and two aspherical lenses.
- Super Multi Layer (SML) coating reduces flare and ghosting from which digital cameras tend to suffer. 

THE SPECIFICATIONS
*Focal Length :18-50mm *Minimum Aperture :F22 *Lens Construction :15 Elements in 13 Groups *Angle of View :69.3 ?- 27.9 ? *Number of Diaphragm Blades :7pcs *Minimum Focusing Distance :28cm (11in.)
*Maximum Magnification :1:5 *Filter Size :67mm *Lens Hood :Petal-type hood *Dimensions :Diameter 74.1mm (2.9 in.)X Length 84.1mm (3.3in.) *Weight :445gr/15.7ounces
* The appearance, specifications, and the like of the product are subject to change for improvement without notice.

Optional Accessories
SIGMA EX Multi-Coated UV 67 mm Filter
SIGMA EX Wide Multi-Coated Circular PL 67 mm Filter