When photographing a really big subject, you better have a really wide-angle lens. Better yet, make that a wide-angle zoom. Sigma’s new 8-16mm f/4.5-5.6 DC HSM lens is just that with the equivalent angle of view of a 12-24mm lens on an APS-C DSLR like the Canon 7D. Take a look at the following comparison of different viewing angles.
The Sigma 8-16mm lens is the widest ultra-wide angle lens without going into a fisheye. The 8mm range provides an ultra-wide view over lenses like the Canon 10-22mm EF-S @ 10mm. You should also note that there is a clear difference between a Fisheye lens and a Wide-angle lens. Wide-angles are manufactured to minimize/correct for barrel distortion while Fisheye lens are intentionally distorted.
You may have heard about Canon’s just announced 8-15mm f/4 L Fisheye lens. This lens is only a true 180º fisheye for full-frame sensors like the Canon 5D Mark II. Since it is called a Fisheye, I would expect it to still distort like a fisheye lens on a APS-C sensor camera like the Canon 7D. (Take a look at my article from the Canon Expo 2010 testing the Canon 8-15mm L lens and you can see the curving of the straight lines, a clear sign of barrel distortion.) As a result, the Sigma 8-16mm lens is the widest wide-angle available for Canon or any other DSLR.
Sigma 8-16mm f/4.5-5.6 DC HSM
The Sigma 8-16mm lens has an equivalent angle of view of a 12-24mm lens when used DSLR with an APS-C size image sensor. Sigma’s new FLD glass elements has the performance of fluorite glass to compensate for color aberration. One hybrid aspherical lens and two glass mold elements provides excellent correction for distortion and astigmatism.
I spent a few days shooting with the Sigma 8-16mm lens on my Canon 7D. The hyper-sonic motor focuses very fast and accurately while producing sharp images with minimal distortion. The lens handles very well. Take a look at the following night shots.