Quite right. My mistake.
Originally Posted by jbbooks
The one thing with DOF is - as you do too say - that the final magnification of the image is what counts.
The other thing is that it depends on what someone thinks to be still acceptable or already unacceptable.
The third thing that it is a comparative thing too: DOF is much larger in an image in which the 'true' sharpness is nothing to write home about than it is in an image in which the 'true' sharpness is incredibly detailed.
So the final thing about DOF is that we should not be bothered with the thing beyond a very basic level. (Which is: Put focus where it needs to be, and then use the aperture to control how the other bits look. No use in trying to quantify the thing. No use in format comparisons. All that counts is how your image turns out.)