Walter Glover wrote:... I had difficulty with tonal separation. The sky and the painted masonry merged .... even to the naked eye. A Polariser ended up being the solution.
Years ago when I sat in a gallery director's chair (unearned privilege) and had people bring me black and white portfolios for assessment I used to look for tonal "near mergers" in their photographs as a mark of competence. A minute step where bright skin just separates from a light background or a blank sky that falls just below paper base white along the top edge never happen by accident. Only people who command what they are doing can turn these effects out on demand. The alternative, as any mug knows, is to drop on a red filter and consign shadows and sky to black.