The Vivitar Macro 2x TC I have has about 25mm built-in extension. I _think_ it's a 6-element, Kiron-made TC. It has A contacts, but no autofocus capability. These things go routinely for about $40 to $50 at camera swaps (probably cheaper on eBay), and seem to be quite common. I think Vivitar markets new ones; they may not be as good as the older ones like mine.
Christian wrote:
I should look into the Vivitar 2x TC. Which one would you recommend? I think they have a 7 element version that's supposed to be optically pretty good.
My Sigma 2X doesn't work due to the rear-element of my vivitar 105/2.5 Macro hitting the front element of the TC. I have used both the 2x and 1.4x sigmas on my sigma 300mm Macro with good results. But the 300 with a 2x TC is hard to focus and being pretty heavy is hard to chase bugs with.
