inspite of weakness on 8 mm with recommendation of this lens

very good sharpness at 12-16 up to the corners; If stopped down a few very nice pictures high contrast and beautiful colors

expensive; some CA's especially on 8 mm

Sigma 8-16mm f/4.5-5.6 DC HSM review by Yucel

I love the Tokina 11-16mm... Recently got a D800... So was investigating options. Tried the 12-24mm Sigma version II... I prefer the corner sharpness and image usability in the 8-16 shoot DX on the D800 over shooting the 12-24 FX on the D800... The 12-24 is going back to Adorama...

Wide, so very wide; Price is so very reasonable, Sharp, pretty sharp

Not FX ..; But good enough in DX even on FX

With mounts for Canon, Nikon, Pentax, Sigma and Sony, the Sigma 8-16mm f/4.5-5.6 DC HSM is the widest APS-C optic on the market... It offers a full-frame equivalent focal length of 12-24mm and has a variable maximum aperture of f/4.5-5.6.

The Sigma 8-16mm F4.5-5.6 DC HSM is the only one of its kind. This is the first ultra wide zoom lens with a minimum focal length of 8mm, designed specifically for APS-C size image sensors.

Sigma AF 8-16mm f/4.5-5.6 DC HSM (DX) - Review / Lab Test Report

Their latest addition (as of the time of this review) is the Sigma AF 8-16mm f/4.5-5.6 DC HSM. Besides being the most extreme rectilinear ultra-wide lens on the market it is also the first one to sport Sigma's latest new innovation - FLD glass elements.