Sigma lenses have proven to be excellent choices for me since my first (of now 4) lense. Pleasing photograph results has netted my confidence and trust in the name. Certainly a bargain investment in my unprofessional opinion.
One of the users I've discovered that nobody has mentioned is as a macro lens. There I said it. I put a Kenke 12mm extension tube on it and just wow! No need to buy the 100 or 180 macro lens as this covers all ranges. I have a 50d crop camera and a 6d full frame camera so all my lenses are very versatile. Range is 70 ff to 320 crop frame with macro as a bonus and this lens is about as much a value as you will find anywhere. I won't repeat all the effusive praise others have written except to say I concur with most of it.
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