Sigma has introduced an 18-35mm f/1.8 constant aperture zoom lens designed for DSLRs with APS-C sized sensors.
The zoom is the first zoom lens ever to achieve a maximum aperture of f/1.8 throughout its zoom range.
With a focal length range equivalent of 27-52.5mm in 35mm format, the lens has been designed as a standard, everyday or walkaround lens.
The new lens fits into Sigma's range of "Art" lenses, which are designed to offer the photographer the most creativity, such as wide apertures.
Previously, the widest aperture a zoom lens has been capable of achieving is f/2.8, leading many photographers to include at least one prime (fixed length) lens in their kit bag.
To achieve such a wide aperture, Sigma engineers have had to compensate for several complicated problems including distortions and aberrations.
This lens incorporates a wide glass-moulded aspheric lens and Special Low Dispersion glass. Internal focusing and zooming is included, meaning you can use a filter on the front of the lens as it does not rotate.
Other features of the lens include special Super Multi-Layer Coating to reduce flare and ghosting and a minimum focusing distance of 28cm. A hypersonic motor is included for fast and quiet autofocusing. A 9-blade rounded diaphragm is designed to render out of focus areas attractive.
The lens has a brass made bayonet mount, and is compatible with Sigma's USB Dock for optimising lenses. It will be made in Japan.
The Sigma 18-35mm f/1.8 DC HSM price is yet to be confirmed, as is the availability date.