As a first step into macro using my new D90 I am thinking of getting some extension tubes, as the Nikons are allmost as expensive as a macro lens has any one got other reccomendations or comments about the Kenko range I will use it with the 18-105mm kit lens, 70-300 zoom and also some of my old manual focus AI S lenses. I am new to DSLR photography and current lenses so all advice is welcome particularly on an eventual set up to photograph insects in detail ie which lens to a maximum of say £1000.