Hey gang, I have the 2x and 1.4x teleconverters, and I noticed a very strange bonus feature when coupling them together. The 1.4x loses 1 full stop of light. The 2x loses 2 stops of light. So, per the chart below, an f/2.8 lens will be an f/5.6 lens with the 2x attached. However, when adding in the 1.4x tc to the 2x, the f/2.8 lens STILL shows f/5.6 and has use of ALL of the autofocus points. This doesn't make ANY sense, but I'll take it!!