Archived posting to the Leica Users Group, 2001/07/24[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]
> Austin Franklin writes: > > > 2700DPI only approaches the limit of quite > > grainy films. > > 2700 dpi is 53 lp/mm. It is very difficult to achieve 53 lp/mm > with handheld > photographs because of camera shake (and most of my photos are handheld). I believe your premise is flawed. You need to sample at slightly more than 2x the maximum frequency you want to acquire. A scanner IS a data acquisition system. 53 lp/mm is 106 lines/mm, which, as you say, is ~2700 SPI. In order to assure that the scanner can actually "acquire" all the lines, both black and white (which is what a line pair is), you would need to sample at > 5400 SPI.