A teleconverter is attached to a camera lens to increase the focal length and therefore the magnification or zoom. Teleconverters are useful, but they also have some disadvantages.
Should You Buy a Teleconverter?
Most photographers have a telephoto lens in their kitbag. These lenses are great for getting up close and personal with subjects when it’s impractical to physically get closer. However, there are times when even our strongest telephoto lens won’t get us close enough to the action and we need a little more zoom. One option is to invest in a new, longer lens, although this solution can be expensive and isn’t always a viable option.
A cheaper way to increase the focal length of a lens is to purchase a teleconverter (or extender). A teleconverter looks like a compact lens and mounts between the camera body and the lens. It multiplies the focal length of the lens it is attached to. Teleconverters range from 1.4x magnification to 2x magnification.
These tools work well in certain circumstances:
