The quality of the windscreen has nothing to do with that of Raynox. Screwed on my 70-200mm f / 4 Canon, I get a rate of magnification and a close image quality than my 100mm macro! It is a two diopters windscreen: once screwed to the front of the goal, it set to infinity, the focus is at a distance of 50cm between the front lens and the subject. We can use a real focal length (200, 300mm ...) to 50cm from the subject. Hence its name (500d = 500mm). Of course, we can further reduce the distance focus. It retains all the automation, stabilization and autofocus. Unlike extension tubes, there is no light loss. You can also use a smaller diameter lens with a simple adapter from a few euros. It is so effective that I bought in two diameters (72 and 58mm).
