Sigma 150-600mm f/5-6.3 DG OS HSM Contemporary with TC-1401 Teleconverter for Canon EFThe Sigma 150 600mm 5 6. 3 DG HSM OS Contemporary was created around the concept of maximum portability meets utmost image quality in a variable aperture hyper telephoto zoom lens. Light weight and compact, this zoom can handle any long reach photographic situation one may encounter. This 150 600mm Contemporary boasts updated Sigma technology such as a quiet and optimized Hyper Sonic Motor (HSM) and a new Optical Stabilizer (OS) with an accelerometer