Review of the Sigma 10-20mm F3.5 EX DC HSM Canon lens

This lens was specially designed for APS-C-format cameras. Three of its four aspherical lenses are made of low-dispersion glass elements — specifically, 2 ELD (extraordinary low dispersion) lenses and 1 SLD (special low dispersion) lens.Its minimum focus distance is 24cm, regardless of focal length, and the maximum reproduction ratio is 1: 6.5.Tests and reviewsSigma 10-20mm F3.5 EX DC HSM Canon on a Canon EOS 7D cameraWhat we liked:Good distortion correction (especially for a wide-angle zoom).Very reasonable vignetting at maximum aperture.Excellent resolution for this type of lens.What we didn’t like:Significant chromatic aberrations.The weight.ComparisonSigma 10-20mm F3.5 EX DC HSM