But in general, my advice is to NEVER shoot an HC lens any smaller than f11. Even f16 shows noticeable softness, and 22 is a joke, and let's not even talk about 32 or 45.
I guess now we know why Michael did not use F22 when doing a quick comparison of the Canon G10 P&S and the P45+. The results might have enraged you all.
He used the P45+ at F11 and the G10 at F3.5. On A3+ size prints, both images looked virtually indistinguishable, except for the shallower DoF of the P45+, which sort of gave the game away.
I've always been a bit suspicious of the resolution of 8"x10" film when using F64, which gets you approximately the same DoF as 35mm at F8. I think it's understood that you cannot get tack sharp images at F64, even with Large Format. But what you do get with such a large format is better tonality, smoother gradations and far less grain. These qualities are sometimes more important than the ultimate in resolution.
It's also a fact that, whilst at F64 the plane of focus will not be as sharp as it would be at F22, the parts furthest away from the plane of focus will be far sharper at F64 than they are at F22.
In fact, the difference in sharpeness at the plane of focus, between F22 and F64, will be far less than the difference in sharpness away
from the plane of focus, depending on the depth of the scene of course.