[Brightcolours]

This is an APS-C lens with an APS-C image circle - you may argue with 1.55x or 1.6x there but that's about it.

Or 1.51x or 1.53x, it very much depends on which sensor in which Nikon APS-C body.

 

Klaus, since you have the lens and the bodies to try, could you mount it on the 5DS-R to see which part, if any, this lens actually will provide an FF image circle? 

I know that most UWA zooms will have no black vignetting at the longer part of the zoom range, and that most standard APS-C zooms have no usable range on FF. How is that with this portrait zoom? Is the long end actually black vignet-free?