I recently picked up a beautiful tamron 70-210/3.5 to use with an E-M10. It works great with an adapter with tripod attachment and is good even adding the Olympus B300 1.7x teleconverter. Still have to try the focal reducer My problem is: how do you deal with the IBIS focal lenght with a zoom? Do you keep changing it? Do you set it to something in the middle? Turn it off? And then: what do you think is better when your lens is something like a 714mm? Better set it to 600 or 800? I suspect the best answer is just to try but maybe there is something about IBIS al super-tele that I can learn. EDIT: IBIS wants the actual focal lenght, so 357mm for the TC, then probably 400mm is the best option (got confused with the numbers).