I'm aware of two devices that can extend the reach of a lens: the teleconverter and the extension tubes. What else would they have in common, and where do they differ? Are there situations where one ...
Right now, I have a Nikon 18-200mm f/3.5-f/5.6 VR lens. I like it, but want more telephoto range and would also like to be able to use faster shutter speeds. I am interested in the 70-200mm f/2.8, but ...