I know the sky needs replacing. But I would like some advice on sharpening. I was after a lovely crisp architectural shot, I'm going to try some of these in B&W but the colours were important in this one. I have autocorrected levels and contrast, but left unsharpened as the settings I tried (in USM of Amount 150%, Radius 0.6 - 1, and low Threshold (1 or 2)) seemed to leave the ivy looking blocky. Any suggestions on how to sharpen for this type of shot?