Well, the Sigma 15mm is the lens to have if you are not lucky enough to be shooting DX and have a Tokina 10-17mm. The 10-17mm fisheye zoom has so many devotees these days, I shan’t waste space singing its praises here. However, since most of my dive buddies had this lens, I noticeably missed it on this shoot, particularly when I saw their pictures after the dive. For some wide angle subjects you just need the full 180 degree coverage, other times, particularly for wildlife you need to zoom in a bit. With the Tokina you can, with FX you cannot. My biggest frustration shooting wide with the D3 was the fact it did not have a Tokina, hardly Nikon’s fault. I was quite surprised by this considering I only started using the lens in the spring of 2007, a few of months before the D3 was announced! To save you thinking it, the 14-24mm, if you could get it working behind a dome, is no substitute as sees only 114 degrees at its widest.

I shot the Sigma 15mm in Guadalupe and was pleased with the spacious images it produced. But such images always look better alongside the high impact face shots, so I needed something longer. With the straight 15mm the white sharks just got too tadpoley – all head and no body at all. With a Tokina 10-17mm you can just zoom in, but on FX I had to find a different solution. I settled on the 15mm with a 1.5x Kenko teleconverter. It does not offer the flexibility of the Tokina, but it did allow me a tighter view.

I have been using the same TC on DX, with the 10.5mm, but I had always used this combination with a tiny 4 inch dome as a wide-angle macro lens. Using the fisheye-TC combo as a straight wide angle lens is not new thinking for FX, Walt Sterns was the first I heard sharing this idea. I mounted it behind the FE2 port and the small port extension ring that, ironically, I have for the Tokina.

The 15mm Sigma and 1.5x TC has a similar angle of coverage as the 17-35mm at 17mm – about 110 degrees. I would say that the 17-35mm is ever-so-slightly sharper in the centre of the frame, but the corners of the fisheye-TC are better and I much prefer the barrel to pincushion distortion. The TC crops out much of the fisheye distortion. On any shoot I’d imagine I’d use both depending on the subject and affect I was after.

For completeness I will quickly mention white balance. The D3 has excellent auto white balance on land. This seemed to work well underwater, when I used it, but I tend to shoot on preset Kelvin white balances underwater. In Port Hardy and San Diego, using my INON Z240 strobes unfiltered I shot at 5400K, which I find reproduces the best green water. In Guadalupe I added Lee 443 gels to the strobes and shot at 4300K. These are the strongest of several gels I use on the strobes, which I chose because I anticipated longer-than-usual camera to subject distances. For more details on strobe filters and white balance see here.