03-27-2012, 12:38 PM
Tanks for that. Sort of expected you would have tried.
On sharpening; most sharpening works like that. Especially if masking is used, since this suppresses sharpening of low contrast edges. However, if deconvolution sharpening is used, and the point spread function is estimated correctly, the sharpening should do no more than compensate for the spatial low pass filtering that is caused by the lens itself, diffraction, the AA filter etc. MTF 50 is only one measure for the resolution of a lens. When the SNR of the file is good enough, a lower MTF, for example MTF 15, can also be very interesting in that contrast for detail with such a high spatial frequency can be restored. And as you will know better than I, the relation between MTF-50 and MTF-15 is not the same for each lens.
On sharpening; most sharpening works like that. Especially if masking is used, since this suppresses sharpening of low contrast edges. However, if deconvolution sharpening is used, and the point spread function is estimated correctly, the sharpening should do no more than compensate for the spatial low pass filtering that is caused by the lens itself, diffraction, the AA filter etc. MTF 50 is only one measure for the resolution of a lens. When the SNR of the file is good enough, a lower MTF, for example MTF 15, can also be very interesting in that contrast for detail with such a high spatial frequency can be restored. And as you will know better than I, the relation between MTF-50 and MTF-15 is not the same for each lens.