After recently having a Sigma 10-20mm lens. Now not working due to it being dropped. Apperture wont go past f/5.6. So am looking at buying a new 1 for doing my landscapes. I am wanting to choose between the Sigma 10-20mm again and the Tokina 11-16mm. What are your thoughts on both the lenses and which one would be the best to buy. I love the Sigma but have seen good reviews and pictures taken with the Tokina as well.