John Gruffydd replied:
My first camera was a Box Brownie, which had an effective aperture of
about F9 and seemed to have a DOF that was larger than it should have
been (subjectively at least) for that aperture. One reason might have
been that most prints in those days were "contacts" (same size as
negative - 6x9). But could it also be that the best circle of
confusion for this single meniscus lens was bigger than we would
expect from a well corrected modern lens, so that the far and near
points at which the circle of confusion became noticeably worse were
therefore further apart? OK, so it was soft everywhere, but that made
the focus less critical and so the DOF bigger.
-------------------------------------------------
An interesting point. However, I think I'd look first at the small size
of the contact print. Since our visual acuity is only about 3 lines/mm
anything resolved at just 3 lines/mm on the film would look sharp on the
contact print. 3 lines/mm is a pretty low optical standard... which is
why the cheap Box Brownie could appear to do so well.
Chuck Norcutt
==============================================
List usage info: http://www.zuikoholic.com
List nannies: olympusadmin@xxxxxxxxxx
==============================================
|