It's a good question, FWIW I would expect a reasonably sharp "L" shaped curve in the focus. The assumption there I guess being that this metric of 'focus' is so

It's a good question, FWIW I would expect a reasonably sharp "L" shaped curve in the focus. The assumption there I guess being that this metric of 'focus' is something well characterized by low-frequency type basis matrices given by the first few rows/columns of the SVD's U and V.