The penalty for using an Ultra Wideangle Lens is that you do have to apply correction to the Geometry if you want "true" horizontals and verticals. One of the reasons that I settled on DxO Optics Pro 6 ELITE software was the ease of making these corrections. In addition, the RAW conversions are superior to ACR and Canon's bundled software. You should try it. Oh, thanks to merrill and yourself for the feedback. This is what keeps one going in photography. Stephen