Sigma have announced the 12-24mm f/4.5-5.6 EX DG Aspherical/HSM.
The large angle of view (122super wide angle of view at 12mm along
the diagonal axis) is ideal for shootings indoor as well as landscape
photography. It has a variable angle of view from 122 to 84.1.
Four Special Low Dispersion (SLD) glass elements are provided for effective
compensation of colour aberration, which is a common problem with super-wide
angle lenses. Two pieces of Glass Mold and one-piece hybrid aspherical
lenses offer excellent correction for distortion as well as all types
of aberration. By effective arrangement of lens elements and advanced
technology this lens has super compact dimensions of 100mm full-length,
and 87mm maximum diameter.
The lens is equipped with an Inner focusing system that will keep the
length of the lens unchanged while controlling aberration. The models,
which are equipped with HSM (Hyper Sonic Motor) system offer Full Time
Manual Focusing. It has a minimum focusing distance of 28mm at all focal
lengths. This lens is equipped with an integral petal-type hood to block
out extraneous light.