C
Charlie Hoffpauir
Thanks, CSM1, but both these links speak to color photos. I need a 1200
ppi scanner for line art, B&W bitmaps.
Charlie says
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You can't get better than 600 ppi resolution on paper documents with
any scanner, no matter what the states resolution is.
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He also says
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This assertion
is based on the fact that a printed document "contains" no more than
about 300 ppi of information.
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I don't believe this is true. I believe line art should be scanned at
1200 ppi minimum for 100% reproduction. Color and grayscale should,
quite appropriately, be scanned at 300 ppi for 100% reproduction.
Thomas
I now see that I must "back off" from that statement.
There are certainly some "documents" that contain more than 600 ppi of
information. (I even alluded to that in one of my posts, indicating
that a second scanner might be needed for high resolution scans).
However, based on my experience, there really is not much, if
anything, to be gained by scanning at the higher resolution "for most
documents".
I have personally scanned several genealogy books to include on our
Family Association CD, (scanning to tiff files and then converting to
PDF for storage on the CD). I experimented with different scan
resolutions, and found that 300 ppi gave excellent results, quick
scans, and good results on those few scans that I converted to text
using OCR (my OCR program recommends 300 ppi scans). Now genealogy
books are usually self published, and the printing is admittedly not
the highest quality.
I use a relatively cheap sheet fed scanner made by "Brother" for
scanning books that I can disassemble, and a "better" Epson photo
scanner (3170) to check out scanning at higher resolutions. The Epson
has scanning settings up to 12800 ppi, which is obviously overkill for
anything. Optical resolution is probably about 1200, which is not
needed for anything I scan (I have a Nikon film scanner for slides and
negatives).
I now admit that your requirements are special. And also still
maintain that my recomendation would still apply for the majority of
people.