Name. Canon calls this the Canon Zoom Lens EF-S 17-85mm f/4-5.6 IS USM. EF: Electronic Focus. All modern Canon lenses do this. -S: Only works on newer, small ( 1.6x factor) DSLRs, which are the 40D, 30D, 20D, 20Da (astronomical), Digital Rebel XTi, Digital Rebel XT and the original Canon Digital Rebel. IS: Image Stabilization. DylbZ9.