High-Index / Low-Dispersion 2 Element Optical Glass | Fully Multi-Coated & Threaded | Anti-Reflection Coating | High Speed Auto-Focus / Infrared Compatible | Nikon D 3300 d3300 - 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. This lens has two achromatic elements to correct chromatic aberrations. They do not degrade the high optical performance resulting from your cameras natural lens.