The beauty of using tilt is that no resolution is lost to diffraction. For more on diffraction, see Making Sharp Images.
On the Nikon D3x, the negative effects of diffraction being to subtly appear by f/8, and there are clear losses of contrast by f/11 (with a high quality lens). MTF charts always show this clearly.
The deconvolution sharpening used here minimizes the sharpness losses from diffraction, so the crops shown are about as good as one can expect with the best sharpening technique.
The tilt function can help evade the image-degrading effects of diffraction: appropriate tilt can allow use of f/5.6 instead of f/16 or f/22, at least with some subjects where the wedge of sharpness achievable by tilt “fits” the subject matter.
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