Lens system
| Maximum aperture number |
22 |
| Diagonal angle of view (max) |
122 ° |
| Diagonal angle of view (min) |
84.1 ° |
| Closest focusing distance |
0.28 m |
| Number of diaphragm blades |
6 |
| Component for |
SLR |
| Focus adjustment |
Auto/Manual |
| Minimum aperture number |
4.5 |
<b>Ultra wide angle zoom lens compatible with digital SLR cameras with 35mm full frame image sensor.</b>
This ultra wide angle zoom lens incorporates the latest optical design provides superior performance. FLD ("F" Low Dispersion) glass elements, which have performance equal to fluorite, and SLD (Special Low Dispersion) glass elements provide excellent correction of color aberration. Aspherical lenses give advanced performance with a compact and lightweight construction. The Super Multi-Layer Coating reduces flare and ghosting. High image quality is assured throughout the entire zoom range. Incorporation of HSM ensures quiet and high speed autofocus as well as full-time manual focus capability. This lens has superior peripheral brightness and provides sharp and high contrast images even at the maximum apertures.
<b>Ultra wide angle zoom lens compatible with digital SLR cameras with a 35mm full frame image sensor.</b>
Sigma designed and produced the first wide-angle zoom lens, the "zoom gamma 21-35mm F3.5-4", in 1979. Sigma has since introduced a number of wide angle zoom lenses. The SIGMA 12-24mm F4.5-5.6 II DG HSM is the successor of the SIGMA 12-24mm F4.5-5.6 EX DG ASPHERICAL / HSM which was launched in November 2003. This ultra wide angle zoom lens is ideal for digital SLRs with a 35mm full frame image sensor and incorporates the latest optical design.
<b>Superior image quality</b>
The ultra wide angle zoom lens is possible due to large diameter of the front lens. Four FLD ("F" Low Dispersion) glass elements, which have performance equal to fluorite, and one SLD (Special Low Dispersion) glass element provide excellent correction of color aberration. Three glass mold elements and one hybrid aspherical compensate for all types of aberration and ensure high optical performance.
*FLD glass is the highest level low dispersion glass available with extremely high light transmission. This optical glass has a performance equal to fluorite glass which has a low refractive index and low dispersion compared to current optical glass. It also benefits from high anomalous dispersion. These characteristics give excellent correction for residual chromatic aberration (secondary spectrum) which cannot be corrected by ordinary optical glass and ensures high definition and high contrast images.
