I recently had the good fortune of doing the famous Kona manta ray night dive. It was a truly once in a lifetime experience to be so close to these amazing creatures. I wrote a report here and the pictures are here. Some highlights are below. I used a Nikon D40 and 12-24 mm lens in an Ikelite housing, with one DS-160 and one DS-125. I'm not happy with the soft corners, but such is a life with a wide angle rectilinear lens. I hope to be able to go back one day with a 10-17 mm fisheye! Hope you like them.
