https://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1676&Camera=1508&Sample=0&FLI=0&API=0&LensComp=1222&CameraComp=0&FLIComp=0&APIComp=0
I was hoping that the new lens would have at least the same IQ as the F4 version. Sadly, it does not. At 2.8 the quality drops. :-(