[awaldram]

[quote name='Klaus' timestamp='1290776738' post='4476']

http://www.imatest.com/docs/sharpness.html#calc



It's not my claim - I'm just a user actually. :-)

[/quote]

Ah there pre-stacking using multiple copies of different blur levels.



"The four bins are combined to calculate an averaged 4x oversampled edge. This allows analysis of spatial frequencies beyond the normal Nyquist frequency."



Not sure I agree with their conclusion though especially given their own corrections.

"Correction 11/22/05: the bin does not depend on the detected edge location."



But the maths is beginning to go above my head <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/blink.gif' class='bbc_emoticon' alt=':blink:' />