The Sigma AF 15mm f2.8 EX DG Diagonal Fisheye is a full-frame compatible ultra-wide-angle fisheye lens with a dramatic 180-degree diagonal angle of view that fills the entire sensor frame. Built for creative professionals and enthusiasts, this lens delivers exaggerated perspective effects and extreme barrel distortion, making it ideal for landscape, architectural, interior, and artistic photography. The bright f2.8 maximum aperture performs exceptionally in low-light conditions while the close 15cm (5.9 inch) minimum focusing distance allows for striking near-subject compositions with wildly distorted backgrounds. Featuring Sigma's DG optical coating to minimise flare and ghosting on digital sensors, 7 elements in 6 groups construction, and a rear gelatin filter slot, this discontinued model combines robust engineering with the optical precision Sigma's EX series is known for.