[davethebirder]

Image stabilization with Sony is one of the biggest mysteries.
* their IBIS is the least efficient - possibly due to the small mount diameter
* they don't offer dual IS, which is even more strange

Normally, I would expect that the latter is a no-brainer for Sony to compensate for their lack of IBIS efficiency, but somehow, they didn't manage to implement this.

Yes the mount limits IBIS ...... in video mode to improve stability, they crop the image slightly so that the image corners don't hide in the shadows of the mount ........ 

fotorrhoe wrote:
There is no limitation by the Mount, simply as VF and APSC implementations are similar in efficacy and the latter should have an advantage if this hypothesis would be true.

   I don't think you are correct in that assumption as the crop in video mode gives significantly greater IBIS stability!

  Cordialement .......