Sigma 15mm ƒ/2.8 EX ED Diagonal Fisheye Underwater

By Michael Zeigler The Sigma f/2.8 15mm fisheye (Sigma 15mm f/2.8 EX DG Diagonal Fisheye) is considered by many as the go-to fisheye lens for full-frame Nikon underwater shooters. Its minimum focus distance of fewer than 6” and its 180º diagonal field of view makes it a great lens for shooting underwater. The Sigma 15mm performs very well behind 8…