Originally Posted by DanC.Licks
You set the IBIS to the ACTUAL focal length. Crop factor has nothing to do with optics. I set the 400 to 400 without the TC and to 600 (actual is 560mm) with the TC.
Thanks for the reply Dan and that makes sense now. So does that Metabones adapter give 2x equivalent? If it does and works with a tc that's very impressive - can't say that I have ever felt the 400 f5.6 and tc on my 70D was up to anything more than 20' for shooting reasonable quality