There are wide angle lens and even ultra-wide angle lens. But, when even those are not wide enough, there is the circular fisheye. There are very few true circular fisheye lens on the market. Thankfully, Sigma has a 4.5mm f/2.8 EX DC HSM lens available for Canon, Nikon, Sigma, Sony/Minolta and Pentax mounts. This is a very unique lens!
|4.5mm F2.8 EX DC HSM Circular Fisheye
The circular 180º field of view produces striking images with exaggerated perspective of near subject & extreme barrel distortion of the surrounding areas
Looking to add a unique look to HD-Video? This sharp lens creates a barrel distortion that looks amazing with moving objects and shifting viewpoints.
Whether it is skyscrapers or trees, you can easily create those perfect photos of soaring heights. In fact, it is the unique 180º circular view which made the the full 360º panorama of Grand Central Terminal possible.
NOTE: See my tutorial on Creating 360º Panoramas with PTGui.