Fujinon 180mm A on an MPP Mk VIII?

[Tom Hoskinson]

Well from those figures, the best performance from Keiths current lens is at f16.

I believe that the lens becomes diffraction limited somewhere around f9. In my experience, (and as expected) my lens also performs acceptably well (to me) at f16 and much smaller apertures. Of course, Acceptability depends on your purpose and goals.