On 26 Sep 2005 at 13:21, mike wilson wrote: > This is what I find paradoxical about the whole "digital revolution". On one > hand, there are statements like the above - 12,000dpi to extract anything like > the full information from a 35mm frame. On the other, there are the "6mp is > enough" brigade. I know they are not exclusive.
Put it this way you can scan film at a resolution that effectively melds the grains which produces manageable file sizes and image files which are readily post processed in the normal manner. Or you can scan at a resolution that captures all grain detail, creates very large files and requires special treatment in order that it can be post processed in a normal manner (filtering needs to be applied that creates a con-tone image). Scanning at a resolution that is close to the grain size can cause difficult to deal with aliasing errors. > That I understand. Is the ISO scale linear wrt grain size? If so, I assume > that to get the same effect from a 25ISO frame you will need to scan at > 128,000dpi. No unfortunately, just check some film grain figures on a film manufacturers sites tech docs (if you can find one these days :-) Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
