for an upcoming vacation I'm pondering if I should add an extender to my EF 70-200/4L (non-IS).
What's your experience with original Canon and third party extenders?
Currently I'm thinking to add a Canon 1.4 converter to limit the quality loss.
How does the 1st version of this converter compare to the 2nd and 3rd?
I had the first version of the 1.4x and 2x when I still had the 70-200 f2.8 L IS. Image quality using the 1.4x was fine; using the 2x I noticed a dramatic reduction in sharpness. Ultimately I sold all three because I wasn't using them.
Over the years I've had a number of teleconverters (Canon FD and Minolta MD, as well as EOS) and rarely used them. I don't bother with them now.
I have a Kenco 2x extender which I find to be excellent. I also rarely use it - not because of quality but because I just do not want particularly long lenses now. The Kenco works with just about all EF lenses, unlike Canon's version.