Archived posting to the Leica Users Group, 2004/02/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Howard Cummer writes: > Hi Luggers, > I have been following the discussion of scanning B&W with Nikon > scanners with great interest. Can someone (Nathan? Tina?) please send > me the settings used to scan Tri X negatives cleanly on a Nikon > Coolscan 4000. [...] I'm still struggling with it. My main problem with my scans of "real" b&w films (e.g. delta 3200, tri-x, ...) is that I end up with *much* more grain in the scan than I see in an old-fashioned enlarger-based print of the same image. I've come to attribute the problem to two factors, a) "grain aliasing", the unfortunate interaction of the grain in the film with the sampling frequency of the ccd grid and b) the highly collimated LED light source in the Nikon scanner, which accentuates grain, dirt, scratches, etc.... If I'm understanding everything correctly, the aliasing problem ought to be similar for any (e.g.) 4000 spi sensor although the various systems' hardware/software might make a difference. The problems caused by the Nikon's light source are definitely avoidable, the diffuse illumination used by my LeafScan 45 gives better/different results. One "solution" to the aliasing problem is to scan with the image _slightly_ out of focus, then use fancy sharpening to tighten up the real features in the image. The theory is that it eliminates the highest spatial-frequency features (like the anti-aliasing filter in front of many digicam sensors) w/out messing up the real features in the image. I can't claim that I'm completely happy with the technique, it's a work in progress, I'm hoping it'll give me better results with my grainy stuff. I'm also searching for opportunities to try some of the other 4000 dpi scanners (e.g. the microtek/polaroid and/or the canon) and see if they're really different. g. - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html