An Art level 20mm f/1.4. The ultimate lens for astrophotography Highest optical performance on a new level Designed for perfect results even in the most demanding conditions Superb build quality and usability with uncompromising attention to detailOutstanding optical quality and a range of invaluable featuresThe ultimate astrophotography lens from the 20mm F1.4 pioneerThe F1.4 series represents the SIGMA Art line, which pursues the highest optical performance and rich expression. The full-frame SIGMA 20mm F1.4 DG DN | Art is a mirrorless version of the SIGMA 20mm F1.4 DG HSM | Art; the one and only lens with its unique specification of maximum aperture of 1.4 and an ultra-wide angle of 20mm. This lens offers photographers overwhelming optical performance and unlimited potential for ultra wide-angle creativity at a compact physical size.The exceptional F1.4 brightness and the breathtaking sharpness across the entire image even at maximum aperture make this lens the ultimate choice for astrophotography. In nightly darkness and focused to infinity, the 20mm F1.4 DG DN | Art captures stars in the sky as clear, precise pinpoints of light. State-of-the-art optical design and the large, high-precision double-sided aspheric glass front element made it possible to add a front filter thread without any compromises regarding optical performance or size. The addition of other invaluable features such as a rear filter holder and a variety of useful switches further increases the creative possibilities and easy usability of the lens. Its incredible sharpness and very bright aperture, coupled with the compact body and thoughtful features, make the SIGMA 20mm F1.4 DG DN | Art the ultimate lens for astrophotography and an ideal companion for any photographically demanding situation.Highest optical performance on a new levelThe SIGMA 20mm F1.4 DG DN | Art delivers exceptionally detailed results that easily satisfy the high demands of professional photography and other high-end applications. With 17 glass elements arranged in 15 groups, including two SLD, three aspherical glass elements and the largest class double-sided aspherical glass element in SIGMA's history, the 20mm F1.4 DG DN | Art rigorously suppresses various optical aberrations such as sagittal coma flare or image distortion to produce highly-detailed images with exceptional sharpness and accuracy from the center to the furthest corners, allowing photographers to make use of the entire field of view afforded by its ultra-wide viewing angle.This ultimate astrophotography lens is the culmination of the unparalleled manufacturing technology of SIGMA's sole production base in Aizu, Japan, as well as the company's know-how and experience with large-aperture wide-angle lenses, such as the SIGMA 20mm F1.4 DG HSM | Art, the SIGMA 14mm F1.8 DG HSM | Art and the SIGMA 14-24mm F2.8 DG DN | Art.Designed for perfect results even in the most demanding conditionsSIGMA's outstanding design and high-precision manufacturing capabilities made it possible to equip the SIGMA 20mm F1.4 DG DN | Art with a front filter thread despite its very large F1.4 aperture and 20mm ultra-wide viewing angle. The lens also comes with a rear filter holder, allowing photographers the freedom to combine multiple filters to suit a huge variety of shooting situations for near-unlimited creative potential at an ultra-wide viewing angle-for example, using a front filter to reduce light pollution and a softening filter on the rear to take impressive photographs of nightly landscapes with star-filled skies.The new MFL (Manual Focus Lock) switch to turn off the focus ring makes it easier to concentrate on the shoot without worrying about accidentally changing the focusing distance. Further, the lens also equips a lens heater retainer, meaning that lens heaters used to prevent internal condensation as the temperature drops on longer night shoots will stay securely attached to the barrel without protruding into the image and causing unsightly vignetting. With its brilliant optical power and its full range of useful features despite its compact and lightweight body, the SIGMA 20mm F1.4 DG DN | Art is the ultimate choice when photographing the night sky.Superb build quality and usability with uncompromising attention to detailIts dust- and splash-resistant structure and the water- and oil-repellent coating on the front glass element make the SIGMA 20mm F1.4 DG DN | Art safe to use during longer outdoor shoots, especially during the night. Thoughtful features such as a focus mode switch, a customizable AFL button, and an aperture ring lock switch enhance the lens usability. An aperture ring click switch can be used to turn the aperture ring click on and off, allowing photographers to enjoy the sound and feel of the click, as well as smooth aperture operation during video recording.The robust body is built from a combination of aluminum and Thermally Stable Composite (TSC), giving it a sleek finish, and the included petal-shaped lens hood is equipped with a lock mechanism to keep the hood securely fastened to the lens, and the rubberized grip area makes attaching and removing the hood a quick and easy process. Manufactured in Japan with an uncompromising approach towards every single detail, the SIGMA 20mm F1.4 DG DN | Art offers photographers an exceptional experience with high-end results even in the most difficult conditions, thanks to its outstanding optical performance, exceptional build quality perfect for professional use, brilliant and precise ergonomics, and a range of useful features.