Perfectly fulfilled its protective role, mounted on a Canon EF-S 18-55mm f / 3.5-5.6 IS lens (58mm diameter). Be careful when screwing. Once in place, I did not note any significant distortion or chromatic abbérations. The filter rammasse all dust and protects my goal, I fear no more, from now on, to keep on hand to be ready to shoot without furnish the protective cap.