The Sigma 24mm F1.4 Art wide angle lens is designed for full-frame DSLRs, and when used on digital cameras with an APS-C size image sensor, it effectively becomes a 38mm. The Sigma 24mm /1.4 lens is ideal for capturing a variety of photography subjects, including cityscapes, mountain ranges, astrophotography and weddings and is great for videography work as well. The 24mm also excels at indoor photography in low illumination thanks to the combination of exceptional focal plane sharpness, and gorgeous bokeh rendered by nine rounded aperture blades. The lens achieves a maximum magnification of 1:5.3 with a minimum focusing distance of 9.8 inches. The 24mm incorporates both "F" Low Dispersion (FLD) glass and Special Low Dispersion (SLD) glass in a design of 15 elements in 11 groups to minimize chromatic aberration of magnification especially in the edge of the image field. Moreover, the optimized power layout includes aspherical elements that are positioned in the rear of the lens for improved wide open performance. This helps to ensure minimal distortion through the correction of axial chromatic aberration and sagittal coma flare. The new lens element design also delivers excellent peripheral brightness. Other updates to this lens include a new full-time manual focusing mechanism that switches to manual focusing, simply by rotating the focus ring, even when AF is being used, first introduced on the 50mm Art. This allows the photographer to make focus