Teleconverters are one of the most useful tools in the photographer's kit bag; they can be mounted between a camera and lens to allow users to increase the magnification of their current lens lineup, without purchasing new lenses. This extra telephoto reach means you can get closer to subjects that your lens would traditionally allow, opening the door for lenses with shorter focal lengths to be used to frame distant subjects; great news for anyone photographing sports and wildlife subjects.
How much of an increase in magnification can you expect to experience when using a teleconverter? The most common magnifications that you will experience are 1.4x and 2x. In simple terms, this means when using a 1.4x teleconverter a 300mm prime lens will provide a 480mm focal length, while when using a 2x teleconverter the same lens will now provide a 600mm focal length.
When using most modern teleconverters your AF system, AE system and other forms of electronic communication between your camera and lens is generally maintained perfectly. Still, there are certain issues that you must be aware of when using a teleconverter. First and foremost, teleconverters are not compatible with each and every lens in your camera bag, so you will have to investigate this thoroughly before making your purchase. Secondly, using a teleconverter will result in a loss of light, meaning the maximum aperture will be slower when the teleconverter is mounted. For a 1.4x teleconverter, expect to experience a loss of one-stop, while with a 2x teleconverter this loss is two-stops. In simple terms, if the maximum aperture of your lens is f2.8, this will change to f4 when using a 1.4x teleconverter, and f5.6 with a 2x teleconverter in use.
Wondering if you can use a teleconverter to increase the reach of your current lens? Feel free to chat with us online or at your local Ted's store.