TC's are always made for specific lenses be it OEM or third party TC's. Even the a novice knows that a TC will degrade picture quality. You can expect a good 2x TC to degrade your image quality by 25% and a 1.4x to degrade about 5-8%. You also will lose two stops of light.
Durable; Easily Interchangeable; Fast / accurate auto-focus; Lightweight; Strong Construction
Poor in Low Light