I was looking for a universal zoom, and so the Objetiv is also zuwangsläugig competed against Sigma 18-250. But the Canon is still high in a different league. I would rather let what focal length away and have an excellent workmanship and optical quality lens, with acceptable Verzeichung at wide angle and excellent sharpness. The criticism in strong vignetting at wide angle, I do not understand. On the one hand this is somehow normal in wide-angle, on the other hand there is the vignette of Canon. That reminds me on rather that the chromatic aberrations much more with a red / blue shift than the Sigma lens. That's one of the weaknesses of the lens. But especially like the base; manually recreate a very robust construction and a very quiet AF motor with the possibility of a great feature Canon.