Extension rings, or extension tubes, are used to decrease the minimum focusing distance of lenses. Therefore, they are used primarily in close-up, macro photography and photomacrography. However, a short extension ring may also be useful to decrease the minimum focusing distance of a long telephoto lens.

What are extension rings used for?

Extension rings, or extension tubes, are used to decrease the minimum focusing distance of lenses. Therefore, they are used primarily in close-up, macro photography and photomacrography. However, a short extension ring may also be useful to decrease the minimum focusing distance of a long telephoto lens.

What is the difference between extension tubes and teleconverters?

an extension tube pushes the lens element closer to the subject. Teleconverters can focus to infinity, an extension tube reduces the maximum focal distance.