FeaturesCompatible with Nikon AF-D mountLarge maximum aperture of f/1.4Floating inner focusing systemHSM (Hyper Sonic Motor) for quiet autofocusSuper multi-layer coatingOne of Sigmas finest creations yet, this lens sets a new benchmark for performance, offering quality that exceeds expectations in every way. Designed with a focus on sophisticated optical performance and abundant expressive power, our new Art line delivers superior image quality for high-level artistic expression. This new lens embodies the concept of our new Art lenses.Compensate for colour aberration to ensure unsurpassed expressive performanceAberration is an important factor for the lens performance. To actualize a high-performance lens, one of the essential elements is aberration correction. When it comes to aberration, there are chromatic aberration of magnification and axial chromatic aberration. It is possible to correct the chromatic aberration of magnification in photo-editing software whereas axial chromatic aberration cannot be corrected afterwards. This lens incorporates FLD (“F” Low Dispersion) glass elements, which have performance equal to fluorite, and SLD (Special Low Dispersion) glass elements, and by optimizing the power alignment of the lens, both types of aberration have been corrected. The lens achieves ultra-high image quality through the entire focusing range. Also, by appropriate alignment of aspheric lenses, astigmatism and field curvature are corrected. The result is superior optimum resolution even in peripheral areas. Large maximum aperture of F1.4 In 2005, Sigma released a lens that has aperture value F1.4 designed for digital SLRs, “SIGMA 30mm F1.4 EX DC HSM”. Since then, we have produced high-performance lenses by incorporating the latest optical technique, such as the standard lens designed for a full size image sensor, the SIGMA 50mm F1.4 EX DG HSM and the medium telephoto lens with large aperture, SIGMA 85mm F1.4 EX DG HSM. This lens, SIGMA 35mm F1.4 DG HSM, is our fourth lens that achieves extraordinary expressive power at the aperture value at F1.4. For wide angle photography, it ensures excellent brightness with the large F1.4 aperture and a beautiful bokeh effect. Attractive blur effect Correction of coma aberration enabled less blur on a point light source in peripheral areas, and the function is best used for astrophotography and illuminations. It is also possible to create an attractive blur to the out of focus areas. The aspheric lens elements used as the first lens have secured peripheral brightness while correcting distortion. The rounded diaphragm creates an attractive blur to the out-of-focus areas of the image. Floating inner focusing system This system compensates for astigmatic aberration and spherical aberration and provides extremely high optical performance for close-up photos. Flare and ghosting conscious design In order to achieve high rendering on this flagship lens, flare and ghosting were thoroughly measured from an early stage to establish an optical design which is resistant to strong incident light such as backlight. The Super Multi-Layer Coating reduces flare and ghosting and provides sharp and high contrast images even in backlit conditions. Hyper Sonic Motor The HSM (Hyper Sonic Motor) ensures high speed and quiet AF as well as full-time manual focus override by rotation of the focus ring. With the enhanced AF algorithm, smoother AF is achieved. Brass made bayonet mount This lens incorporates a brass made bayonet mount which has both high accuracy and durability. A special treatment to reinforce its strength is applied to the surface giving it greater strength and making it highly resistant to long-term use.