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1. 70-200mm f2.8 VRII: The addition of the TC-20EIII teleconverter turns this lens into a 140-400 f5.6 zoom lens. I was extremely (but pleasantly) surprised how well this combination performed. There is slight image softness when shot wide open (f5.6) but stopping down by one stop (to f8) removed most of this softness and produced minimal (and very acceptable) image degradation. This hand-held grab shot of my young Portuguese Water Dog (at 400mm EFL) is typical of the results I regularly obtained using this lens/TC combo. Any decrease in the speed of initial acquisition of autofocus was barely noticeable, but I did notice a slight decrease in the ability of the lens/TC combo to keep fast moving objects in focus (in this case, the number of in-focus shots of my dogs running directly at me was about 40% lower than when I use the 70-200 VRII alone). Focus-tracking subjects moving slightly slower (see, for example, this shot of my other Portie trotting at me at moderate speed) - which represents a scenario more similar to what I would commonly encounter when photographing wildlife in the field - produced a very high ratio of in-focus to out-of-focus images. Overall I found the results of this new 2x TC paired with the 70-200 f2.8 VRII virtually on par with those obtained when pairing the lens with the 1.4x TC-14EII - it's THAT good! There will be very few photographers who will be unhappy with the results produced when the TC-20EIII is used with the 70-200mm VRII.

My Usability Rating for the 70-200mm f2.8 VRII plus TC-20EIII: Moderate to High