KIT SOLUTIONS: TELECONVERTERS ZOOM AND EXTEND

My telephoto zoom isn’t long enough for the wildlife I want to shoot. Can I use an extender with a zoom lens?

Not all lenses are compatible with an extender. I’d urge you to check with the manufacturer of your model to be certain. Extenders generally work with telephoto primes, but zooms can be a different issue.

I use a 100-400mm lens a lot and have both 1.4x and 2x converters that increase its focal length significantly. However, there is a flipside. With the 2x converter, AF is no longer possible. While this doesn’t render it useless, because I can manually focus with it, it does limit its use in the field. If AF does work with a teleconverter, it can be slower and restricted to the central AF point.

There are some other downsides with extenders. Maximum apertures are reduced, which might be fine if you are using a fast lens such as a 300mm f/2.8 prime, but zooms often have a variable range that is not as fast, such as f/4.5–5.6. Image quality can also suffer, but by how much depends on the lens and extender.

Although I think using an extender is a very useful and cost-effective way to increase your shooting range, if doing so reduces quality and AF capabilities too much then it’s not really worth it.