Archived posting to the Leica Users Group, 2000/07/13
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On 13 Jul 2000, at 10:01, drodgers@nextlink.com wrote: > > On 12 Jul 2000, at 15:51, Mark Rabiner wrote: > > > More so than any other color neg film? Not what I can see as I scan > through the > > material. Mark Rabiner How would a color neg film be optimized for > scanning? > > Robert Studdert replied: > > >>Possibly by having a base colour that is more neutral<< > > I'm a little perplexed. If you can filter a color in conventional color > printing -- base, dye or otherwise -- you should be able to filter it in a > digital scan with the correct settings. > > One of the first things that amazed me about scanning was that the scanner > seems to handle various types of film much more easily than conventional > means. When I make my own color prints in the darkroom the greatest > challenge was filtration. Even slight exposure differences caused color > shifts, for which I had to adjust filtration. > > My scanner does an amazing job of handling color. It must be doing > something right in all that prescan buzzing and humming. Hi Dave, What you say is essentially correct however what you must consider is that the digital system has to scan the negative information + colour cast, the CCD isn't the point at which the cast is removed, it is removed by a filter algorithm on the digital side of the system. The CCD (the device responsible for the analogue to digital conversion) has a finite response (10, 12 or 14 bits resolution) so if the CCD is swamped by a particular colour (cast) its dynamic range is reduced to the total ccd response less the colour cast so the less predominant the cast the greater the dynamic range and the deeper the shadow details will be. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 Fax +61-2-9554-9259 UTC(GMT) +10 Hours audiob@ozemail.com.au http://www.ozemail.com.au/~distudio/publications.html