We first heard about the Sigma 20mm F1.4 DG DN Art and 24mm F1.4 DG DN Art here, and now we have some new details. It sounds like these lenses might be designed for astrophotography since the lens has a rear filter holder and a place to install a heater. Wide- angle Art lens attention … Continue reading Additional Sigma 20mm F1.4 DG DN Art and 24mm F1.4 DG DN Art Details