This is an entry level product and one should expect an extraordinary sharpness, especially on the edge of the field ... Otherwise, it will invest more than € 1,000! For 4 times cheaper, but is available with Samyang an honest product that had its effect and allows to embrace on a Canon APS, a field of nearly 180 ° with a good record. Attention, it is completely manual, so we must ensure the development (sometimes to be judgmental, to close objects) and good opening with the LCD of the camera. Shadow point on the board: access to the aperture ring is really not easy, as too close to the circular bayonet fixing; it is not clear the opening level.