On Wed, 30 Dec 1998 16:42:20 +0100, Paul van Walree wrote:
>Neuman - Ruether wrote:
M. K. D. wrote:

>> >The math rules -- depth of field can not be engineered into a lens.

>> Ummm, what about the poor lens vs. the really superb...? ;-)
>> Upon close examination of the images, the sharper lens may
>> appear to have less DOF, since there could be a greater
>> visible difference in sharpness between the in-focus image,
>> and the limits of DOF - as determined by the selected disk

>Ummm, what about the poor film vs. the really superb...? ;-)
>Upon close examination of the images, the sharper film may
>appear to have less DOF, since there could be a greater
>visible difference in sharpness between the in-focus image,
>and the limits of DOF - as determined by the selected disk

Um, yes, of course! Improving either the lens resolution
or the film resolution improves the (potential) image
resolution, thereby possibly reducing the image DOF...
This is a very useful observation (though the original
response was to a comment about *lens* quality...;-).
DOF is a perceptual thing, with many determinants, as in,
"Ummm, what about the low-contrast film/subject-lighting
vs. the really high-contrast...? ;-)...", etc., etc... ;-)