I have barely used Sigma 10-20mm lens. Took 10 pictures only with it. I've changed up my set up and decided to let this one go. 10-20mm F4-5.6 EX DC HSM - Wide Angle Zoom Lenses - SigmaPhoto.com Retail: $740.00 Amazon Used for $459.00 I'm looking for $420 OBO 10-20mm F4-5.6 EX DC HSM A DC series lens designed exclusively for use with smaller chip APS-c or 4/3 cameras HSM (Hyper-Sonic Motor) allows for fast autofocus speeds & quiet shooting and is capable of full-time manual operation Three aspherical lens elements offer excellent correction for distortion and Three SLD (Special Low Dispersion) glass elements employed for effective compensation of color aberration Internal Focusing System allows the convenient use of a polarizing filter for creative effects & improves the optical performance of the lens at various distances Awarded the TIPA award, best consumer lens in Europe 2006 A lens hood, front/rear lens cap and carrying case are included with the lens. Thanks for taking the time to view my ad.