The quality of this windscreen is excellent, close to that of Canon 500d and 250d. His power is 3 diopters: screwed to the front of the lens, this one set to infinity, the focus is at a distance of 33 cm between the front lens and the subject. As the lens is set to infinity, we can further reduce the distance focus. It retains all the automation, stabilization and autofocus. Unlike extension tubes, there is no light loss. I use it on a Sigma 18-250mm zoom macro, the results are bluffing.
