I use these "Weitwinketvorsatz" for 2 months sometimes to a Nikon D80 and have photographed about 50 images after testing it. The intent caused from about 30% distance toward the edge distinct fringing and is at about 20% margin quite blurred. It is therefore shown only about one-sixth of the entire image "error-free". As a substitute for a real wide-angle lens of intent is thus not suitable, but the blur on the edge brings a dynamic to the pictures that make the intent as an effect filter very interesting, it gives the impression as if the edge in movement.
