I wanted to replace my Sigma 18-200 unstabilized DC 2005 by a new versatile product but stabilized for my new Canon 70D. Attracted wide angle and reassured by specialists tests, i ordered the TAMRON 16-300 at AMAZON. Upon receipt, I made a first picture in wide angle and I had a doubt as to the sharpness directly from the screen 70D. Then I realized the same clichés to F3.5 / 6.3 and F8 with two goals on key focal lengths to compare 16-18, 25, 35, 50 80, 100, 200-300mm. The TAMRON is disappointing from 16 mm to 35 mm, less than the old SIGMA. He then became equal to overtake from about 150 mm. I use DxO from the beginning with great satisfaction for each image and I tried with the TAMRON lai, it improves the images but the native resolution is too low to 16 mm. I should clarify that I'm not super demanding and I know the limits of this type of zoom that I use with DxO for 9 years. I use a lot more objective below than above the beach as i turned the lens. He was quickly repaid and I thank AMAZON. I asked myself the question of bad copy, maybe, although I believe that today the production is so industrialized that there is not so much difference in manufacturing tolerances. I did not dare ask for an exchange for the same product. Too bad!