When the lens was first released, I was very curious to see how the Canon EFS 10-22 handles distortion. I decided to compare the level of distortion to a lens I am familiar with, the Nikon 12-24mm. The Canon proved to produce better results, and after looking at images taken by a Tokina or Sigma in a comparable range, I had to conclude that the Canon was the better lens when it comes to distortion. If you do a very scientific test and compare all the results, it is easy to make your own calculations and find that the Canon outperforms the Tokina 12-24, the Sigma 10-20 when you look at distortion. The bit of barrel distortion that does occur because you are dealing with a wide angle lens, after all, can easily be corrected in Photoshop. One or two minor tweaks, and you have brilliant looking, high quality images.