Explains the purpose of stacking teleconverters and how to calculating focal length, aperture, and aperture diameter.
Jan 11, 1999 · Notice! Sigma Apo Tele-Converter EX 1.4X / 2X are dedicated Tele Converter lenses, which should be used only with lenses listed in [Table 1]. If ...
HSM provides high speed auto focus and is silent in its operation. Minimum focal distance supported by this Sigma lens is 220cms with maximum reproduction ratio ...