Appreciate your thorough answer. As it happens, I'd read and re-read Fuji's on line specs, so am aware of Astia's lower RMS value. In comparing neg/pos films, I was curious about a structural difference that would give the advantage to one or the other. I'm too often guilty of drawing conclusions from statements I only think I understand. Therefore, let me ask; however insignificant, do you feel that it's the clear substrate that allows a less grainy image from a scanned positive?
Jack --- Gabriel Cain <[EMAIL PROTECTED]> wrote: > Jack Davis wrote: > > I've never heard or read why it seems to be the case, but I, also, > > realize a poorer image when scanning color negatives than I do when > > scanning positives. Based on posts to this list, I understanding > this > > to be the common experience. At least there appears to be a > "drudgery" > > factor associated with negative scanning. > > I find them equally annoying to scan (at home, with a DiMAGE Dual > Scan IV) :) > > > I was reminded of it today when a deeply experienced lab person > made an > > aside comment, "neg scans are always grainier than slide scans". > > Very difficult, and probably moot at that, to compare RMS factors > > between the two. > > I wonder about the results of a grain comparison between Reala 100 > and > > Provia or Astia 100F. > > Astia 100: > > 18. DIFFUSE RMS GRANULARITY VALUE ................. 7 > Micro-densitometer Measurement Aperture: 48 µm in diameter. > Sample Density: 1.0 above minimum density. > > 19. RESOLVING POWER > Chart Contrast 1.6 : 1 .......................... 60 lines/mm > Chart Contrast 1000 : 1 ........................ 140 lines/mm > > Provia 100F: > > 16. DIFFUSE RMS GRANULARITY VALUE ............. 8 > Micro-densitometer Measurement Aperture: 48 µm in diameter. > Sample Density: 1.0 above minimum density. > > 17. RESOLVING POWER > Chart Contrast 1.6 : 1 ................... 60 lines/mm > Chart Contrast 1000 : 1 ................. 140 lines/mm > > Reala 100: > > 12. DIFFUSE RMS GRANULARITY VALUE .............. 4 > Micro-densitometer Measurement Aperture: 48 µm in diameter. > Magnification: 12 X. > Sample Density: 1.0 above minimum density > > 13. RESOLVING POWER > Chart Contrast 1.6 : 1 ................. 63 lines/mm > Chart Contrast 1000 : 1 ................. 125 lines/mm > > > I know the lab person well enough not question him about his > reasons. I > > would predict a quick flip off remark such as "I see it all the > time". > > I predict that I'll soon not be worrying about such things to the > same > > extent. > > Another factor to consider is that with slides, there is a clear > substrate > that you deal with, but with color neg, there is the shaded mask > substrate. > > > Anyway, anyone have an opinion or, even better, a conclusive > answer? > > This data comes from Fuji's online spec documents. Clearly, Provia > 100F > wins for grain size, but only by a little over Astia 100. > > Gabriel > > -- > Gabriel Cain Dreaming Crow Forge > President and Chief Artifacer P.O.Box 15605 > [EMAIL PROTECTED] Seattle, WA 98115 > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
