Archived posting to the Leica Users Group, 2004/09/07
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Absolutely - And that then requires either using one of the noise-removal programs, which can to quite a good job, or burning in those shadow areas. But either way, it's quite different from dealing with grain in a film image. -----Original Message----- From: lug-bounces+bdcolen=earthlink.net@leica-users.org [mailto:lug-bounces+bdcolen=earthlink.net@leica-users.org] On Behalf Of Adam Bridge Sent: Tuesday, September 07, 2004 4:17 PM To: Leica Users Group Subject: [Leica] How digital noise is different from film grain (my bestdescription) Today I was spotting some black and white scans and the difference between digital noise and film's grain leaped out at me. In film, as you move into the blacks, they become denser and denser as the grains converge. So blacks are black. But in digital the noise happens IN the blacks - adding speckles of light where there should be black or at least very dark. The worse the noise the higher up the luminance values the effect becomes. So at 100 you see nothing in the very dark areas but by, say 400 there are subtle flecks of brightness creeping while while at 1600 these effects are moving well up into the mid-tones. So when you look at a digital image or a film image there is a definite quality difference between the way noise and grain operate in the dark tones. Adam _______________________________________________ Leica Users Group. See http://leica-users.org/mailman/listinfo/lug for more information