SIGMA CONVERTER TC-2011 F/L-MOUNTThe SIGMA TELE CONVERTER TC 1411 TC 2011 are teleconverters designed exclusively for the use with SIGMA L Mount lenses. Mounted between a lens and a camera body, the TC 1411 magnifies the focal length of the camera by 1. 4x, and the TC 2011 by 2x. The superior optical performance of the SIGMA Contemporary, Art and Sports lines of lenses is the result of efforts to pursue the highest levels of image quality. The SIGMA TELE CONVERTER TC 1411 TC 2011