you are trying to define some sort of "absolute" DOF which really doesnt exist unless you consider a certain COC as perfect.
The entire thread and original post was all about the relative DOF ( how to increase or decrease DOF in an image relative to ANY reference DOF ). JC O'Connell [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Matthew Hunt Sent: Tuesday, April 07, 2009 9:27 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field On Tue, Apr 7, 2009 at 9:17 AM, JC OConnell <[email protected]> wrote: > I dont agree with that terminology, it's his not mine. > DOF is relative sharpness of foreground and background objects in an > image compared to the objects in the plane of focus. ( just my working > terminology FWIW). So, if a certain object in the foreground is half as sharp (or twice as blurred) as an object in the plane of focus, is it within the DOF? What if it's a third as sharp? A quarter? Where do you draw the line? To define the DOF, you need a concept of "acceptable sharpness" or "acceptable circle of confusion". These criteria typically arise from assumptions about the final print (film size, print size, viewing distance...). In our previous discussion, I provided a number of reputable citations discussing the origin of these criteria. If you had read them, instead of screaming unsubstantiated assertions back at me, we wouldn't have to go through this again. -- 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. -- 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.
