Sigma has announced it is to release two improved lenses in its line-up.

First up, the 50mm f/1.4 slots into the company's Art range. It has ben reengineered and redesigned to a new standard of performance, according to Sigma.

The lens is primarily designed for full-frame DSLRs, but it will also work on APS-C (cropped) sensor cameras, where the equivalent focal length will be roughly 75mm.

It has been updated to include SLD glass, while other updates include an optimized autofocus algorithm for smoother focusing and a floating focusing system to reduce lens movement while focusing. It also now features 13 elements in 8 groups, compared to the previous 8 elements in 6 groups and improved close focusing at 15.7 inches.

The other improved lens is an 18-200mm f/3.5-6.3 Macro lens is designed as an ideal alternative to standard kit lenses.

Compact

This super-zoom lens now incorporates Special Low Dispersion (SLD) elements for correcting chromatic aberration at the telephoto end of the lens. Aspherical Lens elements also help with distortion correction as well as making the lens smaller and lighter.

As well as being smaller and lighter, the lens now has improved macro focusing capabilities and an improved maximum magnification ratio.

Both new lenses incorporate Sigma's Hyper Sonic Motor (HSM) system for quick and quiet autofocusing. They both also include Super Multi-Layer Coating to reduce flare and ghosting.

Sigma's USB dock and the company's Mount Conversion Service are both compatible with the new lenses.

Pricing and availability has yet to be announced.