So, while there’s no doubt that the Tamron 70-200mm VC is a mighty lens (heck, I just rented one from our rentals department to shoot the IRT‘s charity fundraising event and found it to perform without a hitch in demanding theatre stage lighting conditions), there has been some confusion floating around about using it with tele-converters. Traditionally, 70-200′s have been popular to try and combine with tele-converters, since it gives you the flexibility of having a fast standard tele and then a longer, if softer, tele in a pinch without needing a second lens. I was told (and have confirmed) that the Tamron 70-200mm doesn’t work with either of Tamron’s tele-converter lines (the standard or the premium SP ones). It’ll mount safely, but no auto-focus will work. But, I’ve seen people claim that AF does work for Canon bodies with it (see here).
So, confused, I reached out to our Tamron rep to see if I could get some clarification. What I got back was more interesting still. I won’t name names or post the response verbatim, but what we got back from Tamron’s tech department is that neither of the tele lines are intended for use with digital bodies, and they won’t guarantee the functionality of them on digital bodies. Further, Tamron does not recommend the use of any of their VC lenses with a tele, as the calibration of the VC system does not anticipate the extra glass added by a tele and results can’t be guaranteed. So, there you have it peeps. The Tamron 70-200 VC is a stellar lens with fast AF performance and killer optics, at a price way easier to reach than the big guys’ own offerings. But, if you’re the sort who wants to be able to slap a 2x tele-conv in the pipeline it’s probably not the lens for you. Just a heads up.