Treated myself to the new Ultra wide angle lens from Tokina with a constant F2.8 aperture
The quality of this lens from Tokina is great. Really good sharpness right into the corners when you stop down to about F5.6. It has replaced my Sigma 8-16 for most of the wide angle shots. The centre sharpness is excellent and there's less lens flare than the older 11-16 version from Tokina. I'm happy!