3) Activating map sharpening results in mtz files that look just normal and open in coot after the typical map calculation break, but no maps are displayed. This is independent of the sharpening factor I choose (between 5 and 60).
I haven't used coot for map sharpening, but using the ranges I'd usually have to use (in cad) to seen an effect are more in the 80-120 range. You might want to start with an unrealistically large value just to ensure that things are working, then back off to a better value.
Pete
