DEAR RICHARD, The first I saw of this was on page 267 in my copy of Cox PHOTOGRAPHIC OPTICS (13th ed, 1966). The first edition was published in 1943 and I believe it had the same two images showing that the image that had more resolving power (holding more detail) actually had less acutance (perceived sharpness). CHEERS! BOB -----Original Message----- From: pure-silver-bounce@xxxxxxxxxxxxx [mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of Richard Knoppow Sent: Tuesday, June 01, 2010 9:02 PM To: pure-silver@xxxxxxxxxxxxx Subject: [pure-silver] Re: Film Still Wins ... Even Compared To Leica 18MPix ----- Original Message ----- From: "Peter Badcock" <peter.badcock@xxxxxxxxx> To: <pure-silver@xxxxxxxxxxxxx> Sent: Tuesday, June 01, 2010 5:45 PM Subject: [pure-silver] Re: Film Still Wins ... Even Compared To Leica 18MPix > The author claims that > > "*We know that there is a tight correlation between the > recording of fine > detail and the sharpness of the edge of major subject > outlines. The more > resolution you have, the better the edge contrast and thus > the overall image > sharpness.* " > > I thought Barry Thornton debunked that myth in his book > Edge of Darkness. > Barry has example photos using Kodak Technical Pan 25 ASA > film exhibiting > less sharpness than higher ASA films. Of course Technpan > has more > resolution/finer grain. > > rgds > Peter > > > On 2 June 2010 06:45, Tim Daneliuk <tundra@xxxxxxxxxxxxxx> > wrote: > >> http://www.imx.nl/photo/Film/page169/page169.html >> > Barry Thornton must have re-invented the wheel. The point was made by C.E.K Mees, of Kodak Research Laboratories, in the 1940s, if not before. The term "acutance" was invented by Kodak to mean the effect of edge contrast on "perceived" sharpness. It applies to film but a similar effect is produced in digital processing. In fact, "sharpness" and edge contrast are only partly related. Its quite possible for a film or a lens to have very high resolution but poor acutance. The oldest illustration of this is in a book on basic photography by Mees (although I think its a doctored illustration). Its of interest that the distortion of edges by high acutance developers can actually reduce resolution. -- Richard Knoppow Los Angeles, CA, USA dickburk@xxxxxxxxxxxxx ============================================================================ ================================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there. __________ Information from ESET NOD32 Antivirus, version of virus signature database 5165 (20100602) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ============================================================================================================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there.