Very qualitative objective both in construction as the images it produces professional quality. Superb dive at full aperture, Colors Respect, pleasant Bokeh, fast Autofocus. Vigilance still on Autofocus: the first copy received was very "capricious" on a cannon 6d. Blur, net, blur, Net ... Back made from Amazon, and receiving a second copy, perfect. A test then. Possibility also to improve this with Sigma 878955 Dock USB Cradle for Canon Lens Black. I take great pleasure now with this, I will keep a long time ...