Basic question, I'm sure it's been asked a hundred times but when I
searched around I still couldn't find a definitive answer.
There is no one definitive answer. We are troubled with many different
opinions and situations.
I want to scan documents.
What's the best resolution to scan at?
How should I scan (line art/grayscale/color)?
Are the documents themselves suitable for line art, or grayscale, or
color? That will be your best guide.
Use line art if you can, don't if you can't.
The documents are all letter or legal size and I want them to show up
very clean and clear in a PDF. I also want them to appear at least
"copy machine" quality when printed out. I will be scanning literally
thousands of pages and I want to make sure I don't have to do them all
over again!!
The answer may be different for thousands of pages. For example, a 3 MB
file per page result might be acceptable for a page or two, but likely
quite unacceptable for thousands of pages. Quality is a good goal until
file size hurts too much, then quality may become more secondary.
Basically, I want to know what the best settings are to get decent
document scans.
If line art will do the job (black text on white paper), and speaking of
printing the copies, then 200 dpi line art is good fax quality, possibly
good enough in some cases. 600 dpi line art is near as good as it gets,
virtually perfect, but probably more quality than you need. And 300 dpi
line art is an excellent compromise, and likely all you need for text
documents (no pictures). Acrobat will use G4 compression on line art,
which will be a very small file - 300 dpi is possibly no more than 100KB
per page (depends on page, how blank it is). Size wont be a huge issue
for line art.
If you must use grayscale or color to capture the original, then file
size of 1000 pages will be a huge issue. About the only viable solution
(for file size) will be to use JPG compression. This introduces its own
problems - JPG is tough on text documents. Probably about 150 dpi scans
is all the file size you can bear. Even low JPG quality is near 1/2
megabyte per full page at 150 dpi color scans. 1000 pages approaches
1/2 gigabyte.
Before scanning thousands of pages, it is prudent to experiment a bit
with only a few pages (including actually printing the results) to judge
what factors are important to your own criteria.
If you just need PDF, and can "print" the original text source files to
PDF (to create PDF that way), that will be vastly better and smaller in
every way. All those hundred page PDF manuals that we see everywhere
were done that way--- they are certainly NOT scanned pages. People tend
to confuse that.
