« on: September 30, 2013, 03:50:35 PM »
The IS on the mk II 70-200 f2.8 L IS is indeed much quieter. However, my f/4 L IS seems 4 stops effective while my f/2.8L IS II seems ... 1 stop effective! True this is my subjective view due mainly to lens weight but the end result is the same for me.The IS on the f4 L IS isn't quite as good as the one found on the f2.8 II versionSays you. Canon says otherwise (that they are equal).
In my experience, they are similar, which means highly effective.
The IS on the mk II 70-200 f2.8 L IS is quieter and visibly smoother in the viewfinder. The unit on the f4 LIS is very effective but it's a fair bit older in design than the newer f2.8 version. There's a number of reviewers who have stated that they found the f4 LIS to be slightly less than 4 stops ability and the f2.8 II LIS to be slightly over. Regardless of outcome, both are very capable units and very capable lenses.