----- Original Message ----- From: "JC OConnell" Subject: RE: K20D as Scanner
> The length of time it takes to scan a document is solely dependent > on and proportional to the dpi setting and the size of the document, it > would not take anywhere near the highest dpi settings to > match an optical method of duplication IMHO and if you wanted the > highest possible > quality, a scanner could exceed any optical/camera method on large ( > 5x7, 8x10 ) documents. > Printer resolution is in the 300 ppi (Fuji) to 360 ppi (Epson) range. An 8x10 file optimized for an Epson printer will be 2880 x 3600 pixels. If your prints are being done at what passes for a photolab these days, the resolution requirements are much lower, in the 2400 x 300 pixel range (Fuji), Noritsu is slightly higher (320 ppi). The output from a K20 is 4672 x 3104, ample resolution to do a 1:1 copy of an 8x10 print. For the application that Ken was using the camera for, the K20 has ample resolution, and would likely be faster than a flatbed scanner in real terms. There's no real point in having a higher resolution file if all you are going to be doing with it is discarding unused pixels at the printing stage. There is little point in scanning a print at higher than 400 ppi, as few if any photographic prints will exceed that resolution. At Kodak school, I was told that photographic paper doesn't hold more then ~10-12 lpmm of resolution, and that scanning at any more than 300 ppi is not gaining much, if anything, in terms of real detail, but it does increase the amount of post processing you need to do as you scan more and more paper defects as scan resolution increases. Combine this with the fact that most prints aren't taken with the best cameras, the best lenses, or the finest grained film, and there really isn't any advantage to a flatbed scanner over a modern 14mp or greater DSLR in terms of image quality when copying prints. William Robb -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
