The large angle of view of the Sigma 12-24 4.5/5.6 EX DG ASPH Zoom (122 degree super wide angle of view at 12mm along the diagonal axis) is ideal for shooting indoors as well as landscape photography. It has a variable angle of view from 122 degrees to 84.1 degrees.
Four Special Low Dispertion (SLD) glass elements are provided for effective compensation of color 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. It 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 the HSM (Hyper Sonic Motor) System (only in Nikon, Canon and Sigma Camera Mounts) 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.
Lens Technology Explained:
ASP (Aspherical Lens)
The aspherical lens complex allows freedom of design, improved performance, a reduced number of component lenses and a compact size.
HSM (Hyper-Sonic Motor)
This lens uses a motor driven by ultrasonic waves to provide a quiet, highspeed AF.
IF (Inner Focus)
To ensure stability in focusing, this lens moves the inner lens group or groups without changing the lens' physical length.
EX (EX Lens)
The exterior of this lens is EX-finished to denote the superior build and optical quality, and to enhance its appearance.
DG for Digital (DG Lens)
These are large-aperture lenses with wide angles and short minimum focusing distances. With an abundance of peripheral illumination, they are ideal lenses for Digital SLR Cameras whilst retaining suitability for traditional 35mm SLRs.
Lens Construction:16 Elements in 12 Groups
Angle of View: 122 - 84.1 degrees
Number of Diaphragm Blades: 6 Blades
Minimum Aperture: F22
Minimum Focusing Distance: 28cm / 11 in.
Maximum Magnification: 1:7.1
Filter Size: Rear Type (Gelatin Filter)
Dimensions: Diameter 87mm X Length 102.5mm / 3.4 in. x 3.9 in.
Weight: 600g / 21.6 oz.