The NiSi Close-up Lens Filter Kit NC 77mm (with 49mm & 52mm Adapters) consists of a Close-up Lens Filter that mounts on lenses with 58mm filter thread, as well as two adaptors that will enable the use of this lens filter on lenses with 49mm and 52mm threads respectively. When mounted, this close-up lens filter works like a magnifier to allow a telephoto lens to function as a macro lens. NISi recommends the use of this close-up lens filter with zoom or prime with the full frame equivalent focal length range of 35-250mm, or an APS-C focal length range of 24-250mm. For macro lenses, an inherent focal length of 50mm is recommended. The longer the focal length of the lens, the higher the magnification. (At 120mm, a magnification of close to 1:1 can be achieved). In addition, for obtaining sharp images, the optimal working distance between the lens and subject is between 9 to 22cm. The NC 58mm NiSi Close-up lens filter is constructed with two apochromatic optical corrective glass and features a multi-nano coating to enable high resolution and natural colour with almost no purple/green fringing. At 35mm on a full-frame sensor camera and at 24mm on a APS-C sensor camera, there is no vignetting with this NiSi Close-up Lens Filter. The included 49 to 58mm and 52 to 58mm adapters permits the use of the close-up lens filter on camera lenses with smaller filter threads. A zippered pouch is also included for storing and transporting the entire kit.