The accessory consists of a macro ring which can be used alone and the front lens.
Use "full assembly" must compensate for the loss of about 2 and IL-check the depth of field, which fades in a circular manner around the edges.
Noticed by chance and to explore further, Bokeh effects that seem interesting.
Mounted on a 18-50 zoom, it adds a significant additional weight and double the space (length).
Tested successfully on video, this accessory allows me to gain virtual back to film interviews, good image quality restored in HD.