Add the 1.6X Tele-Converter to the front of your zoom lens to shift its focal range in the telephoto direction. The perfect tool when it's inconvenient, dangerous, or even impossible to move as close to the subject as you'd like. There is no appreciable light loss. Note that the Tele-Converter offers partial zooming. The Tele-Converter is specially effective in "run-and-gun" shooting situations because it attaches more quickly than rear-mount tele-extenders, and doesn't require exposure of the XL1's delicate electronics. Need even more telephoto range? Add the Century 1.6X Tele-Converter to the front of your lens and Canon's 1.6X Tele-Extender to the rear, for the widest possible range with no vignetting. For use with the Canon XL-H1, XL2, XL1S, XL1 with 20x lens.