Canon 8-15 fisheye lens

1 - Introduction
This essay is about a specific lens, namely the Canon EF 8-15, f4 USM fisheye. However, it is also about expressing a personal artistic and photographic vision, the subject of my current focus and research.
Vision can be expressed in many ways and one of them is through the use of gear that allows you to represent the world in a different way.  If you follow my work you know that I distort my images regularly to increase the size of specific elements, to strengthen the composition, or to emphasize the aesthetic appeal of the image.  The Canon 8-15 allows me to do this in camera rather than during post processing. While the possibilities are not as extensive, being limited by what the lens does rather than by my imagination, they are still extensive and worth investigating for their creative potential.
2 - The lens
The Canon 8-15 is a zoom lens. On a full frame 35mm camera, you get a rectangular image with no vignetting in the corners at 15 mm, and at 8 mm you get a cir...