Well, Wikipedia has nice summary for this: In photography, acutance is the edge contrast of an image. Acutance is related to the amplitude of the derivative of brightness with respect to space. Due to the nature of the human visual system, an image with higher acutance appears sharper even though an increase in acutance does not increase real resolution
On Fri, Dec 31, 2010 at 4:20 PM, Mark Roberts <[email protected]> wrote: > Steven Desjardins wrote: > >>On Fri, Dec 31, 2010 at 2:31 PM, mike wilson <[email protected]> wrote: >>> On 31/12/2010, Godfrey DiGiorgi <[email protected]> wrote: >>>> edge definition >>> >>> As good a definition [8-)]as you need for most things. >>> >>IIRC, it can be casually thought of as how (fast) an edge goes from dark >>to light, hence the connection to edge definition. > > That's it. > Acutance is the rate of change between the two sides that form an > edge. Resolution is the number of edges you can put in a given space. > Sharpness is a combination of both characteristics. > > http://www.luminous-landscape.com/tutorials/understanding-series/lens-contrast.shtml > http://www.luminous-landscape.com/tutorials/sharpness.shtml > > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. > -- Steve Desjardins -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
