Optics close-up lenses are for quick and easy close-up photography. The close-up lens is screwed on to the front of a lens like a filter, In this case a stepping ring will allow a larger size macro lens to mount unto a smaller lens opening (This method is acceptable and passes all major brands guidelines). This lens has two achromatic elements to correct chromatic aberrations. They do not degrade the high optical performance resulting from your cameras natural lens.