On this video, photographer Jay P. Morgan from the Slanted Lens takes a look at teleconverters, the advantages and disadvantages of using them.
Morgan isn’t a wildlife or sports shooter but he does know a thing or two about teleconverters and this video looks at the basic things that you need to know if you are thinking about getting one for your camera/lens setup (we will add a few notes of our own just in case).
A teleconverter seems like the perfect solution you add a small optical unit between your camera and lens and you immediately get 1.4x or 1.7x or even 2x the focal length of your lens. If you think about it you can get an 800mm lens at a fraction of the cost (although the aperture will never be like the one of a true pro grade 800mm which cost well over $10k.
So what are the downsides? there are a few – first you loose light – anywhere from 1 to 2 stops (1.4x = 1 stop and 2x = 2 stops), focusing will also usually be slower (and with some lens/camera combinations it simply won’t work – especially with 2x).
The final problem is image quality – when adding extra lens elements that are not part of the lens you loose quality – how much – depends on the lens and the teleconverter but typically the 2X will downgrade the image much more than the 1.4x (a good 1.4x on a good fast lens can still typically give you good images).
We have published quite a few videos dealing with teleconverters and their advantages/disadvantages here on Lensvid including Tony Northrup’s “Teleconverters – Advantages and Disadvantages” and Steve Perry’s “Which is Better – Crop Camera Or Full Frame Camera With A 1.4 Teleconverter?“.