Sigma claims this is the world’s first f/1.4 diagonal fisheye, the unique feature here being its f/1.4 maximum aperture. This alone would make it a very interesting option for astrophotography, where extreme angles of view and extreme lens apertures are highly desired, but Sigma has built in a number of other features to tempt stargazers too.
The Sigma 15mm F1.4 DG DN is a so-called ‘diagonal fisheye’, which means that while there is strong curvature towards the edges of the frame, the image does still fill the frame – as opposed to a ‘circular fisheye’, where you just get a circular image with black borders.
