The Sigma 8 16mm F4 5 6 3 DC HSM
Sigma is the pioneer of ultra wide-angle lenses and the 8 to 16mm F4.5 TO 5.6 DC HSM is a great example of this tradition.
This lens is great for shooting landscape photography, wedding photography, architecture, group pictures and more. Designed specifically for APS-c size image sensors, this lens is the only one of its kind.
It's the first rectilinear ultra wide zoom lens with a minimum focal length of 8mm. And it comes with a four year warranty.
It has an equivalent angle of view of 12 to 24mm when used on a digital camera with an APS-c sensor, so it's extremely versatile with a maximum field of view at 8mm of 114.5º .
It allows you produce images with a very exaggerated perspective -- so it's ideal for big family photos or when you want to capture a sweeping view of the outdoors, or are working in tight quarters and want to take it all in.
Reference: http://vimeo.com/47166584
The official Vimeo Pro Page of Sigma Corporation of America. http://www.sigmaphoto.com/