A wide and fast prime, the 24mm f/1.4 DG HSM Lens is a member of the highly regarded Art line of Sigma's Global Vision Series and is characterized by its advanced optical construction and robust physical design. The combination of three "F" Low Dispersion (FLD) elements and four Special Low Dispersion elements help to achieve a marked reduction in chromatic aberrations, while a pair of aspherical elements, with one positioned in the rear of the lens, minimize a variety of additional distortions and aberrations. The 15-element-in-11-group optical design is poised to deliver consistent peripheral brightness and sharpness, even when working at the bright f/1.4 maximum aperture. A Super Multi Coating has been applied to lens elements, too, to reduce flare and ghosting for higher contrast and color fidelity. Complementing the optical performance is an equally adept Hyper Sonic Motor, which provides fast, smooth, and near-silent autofocus performance. This focusing motor also enables full-time manual focus override at any time just by rotating the focus ring for refined manual control. Nine rounded diaphragm blades contribute to pleasing out-of-focus quality when working with shallow depth of field techniques, and the lens is also compatible with the optional Sigma USB Dock for fine-tuned control over focusing parameters and other lens characteristics. As part of the Art line within Sigma's Global Vision series, this lens' is designed to achieve truly notable optical performance and is ideally suited for creative and artistic applications. The prime 24mm focal length offers a versatile wide-angle perspective when used on full-frame sensors, making it ideal for landscape, nature, interior, and architectural photography. When used with a APS-C-format sensor, the lens offers a 38.4mm equivalent focal length. Fast f/1.4 maximum aperture is well-suited for working in low-light conditions and also provides greater control over the focus position when using shallow depth of field techniques. This lens has been designed using an advanced optical structure to achieve both high resolution and sharpness, along with consistent edge-to-edge illumination. A pair of aspherical elements, with one in the rear of the optical design, correct for sagittal coma flare, distortion, and axial chromatic aberration, while also enabling full use of the fast f/1.4 maximum aperture with maintained peripheral brightness and sharpness. Three FLD and four SLD glass elements have been incorporated within the lens design to correct for chromatic aberrations throughout the entire focusing range and help to ensure high image sharpness, clarity, and contrast regardless of focus point or aperture setting. A Super Multi-Layer Coating has been applied to lens elements in order to minimize lens flare and ghosting and contribute to producing contrast-rich and color-neutral imagery, even in backlit conditions. The integrated HSM (Hyper Sonic Motor) realizes quick and quiet autofocusing, which is further complemented by an optimized AF algorithm to produce smoother focusing performance. The HSM also permits full-time manual focus control simply by rotating the focus ring at any time. A rounded nine-blade diaphragm helps to produce an attractive out-of-focus quality. The lens is constructed using a Thermally Stable Composite (TSC) material, along with traditional metals, for greater precision and use in wide temperature variations. The outside of the lens barrel is also engraved with the year of production. The bayonet mount is constructed from brass for ensured accuracy and durability. The included lens hood is fitted with a rubber connection for a secure fit. This lens is compatible with the optional Sigma USB Dock for fine-tuning different lens characteristics and updating its firmware.
