(English below)Sigma 17-50mm f/2.8 EX DC OS HSM – Obiettivo per Canon EF. Sigma 17-50mm f/2.8 EX DC OS HSM – Lens for Canon EF. A great choice for anyone looking for a versatile zoom with a constant f/2.8 aperture, optical stabilization (OS), and fast, silent autofocus (HSM).
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