What is not to much? I recomend the 10-20mm Sigma. at ?475 its not a monster when compared to others. Its also built very well and is quite impressive in terms of sharpness especially when you stop it down to F8. As for distortion there is a bit (a fair amount to be honest when down to 10mm) but what can you expect from a 10mm lens? Its wide enough to fit Mary Harney in it…