With the SP range, Tamron has improved the quality of its objectives and has set the bar for competition. The Super Performance is waiting for you! A great dive even to 600mm, with the best among f.8 and f.11, silent and swift autofocus, and a more than adequate stabilization, make this objective, and at this price level, one of the best in class . Of course, Nikon and Canon do better, brighter, (f.4 opening for "fixed" targets), but for heavier (the Tamron does not reach 2kg on the scale) and much, much more. In addition, Tamron 5 years guaranteed its objective, which is reassuring reliability. In short, just happiness !!!!