Nikon's 4T is a 2 element, 2.9 diopter macro close up lens. The main advantage is that it gives you working space so that you don't have to get too close to your subject. In addition, the two elements are an advantage for a single element diopter according to some. Like having a multi-element lens. Another big advantage to this lens is that it is very reasonably priced at $30US.

by: Stinson