excellent f/f fisheye for DX cameras, you need to shoot above f4 as it will be soft on the deges below this aperture. Also a cover is essential if you use a large dome port to prevent internal reflection from the gold printing. If you pop a 1/2 diopter lens in the rear filter bay then it will focus on the dome!
Extremely sharp with a large diameter dome. Very noticeable color fringing near the very outer edges if there are high contrast elements at the corners. I gave it 4 because there is no such thing as a ultra-wide digital camera/lens combo that wont produce fringing in the corners.....yet. Close focusing, great saturation and contrast. It out-performs my Nikkor 16mm fisheye.