This is the classic fisheye look for full-frame cameras, just a slightly fishy wide angle lens on a crop frame. There are other 15mm and 16mm full-frame fisheye lenses but we really see no sense in stocking them. The Sigma 15 is as good as any — very sharp, quick to focus, a pleasure to use. All that being said, fisheyes are great fun but you don’t want to go anywhere with it as your only wide angle lens. Most of us tire of the effect after a while.

We get asked a lot (and even worse, not asked by people who don’t know) what the different focal length fisheyes look like on different cameras. Here’s the short summary:

• 4.5mm – is a circular image in the center of your picture on a crop frame camera. A very, very small circle on a full frame.
• 8mm – is a circular image in the center of your picture on a full frame camera. Nearly, but not completely fills a crop frame.
• 10mm – is the classic, corner to corner fisheye look on a crop frame camera. Doesn’t fill a full frame image.
• 15mm – is the classic, corner to corner fisheye look on a full frame camera. Slightly fisheye look on a crop frame.

The Fisheye Comparison Chart under Resources on the right-hand side of this page should give you an idea of what you’ll get with each type of camera.