This is a common question we hear. We rent and sell large format
scanners for archival and digitizing projects.
Although disk space has become very cheap companies are still concerned
with disk space usage.
A test was completed to estimate file sizes. Let’s take a small format example. Our sample is an 8 ½” x 11” standard sheet of
paper or ANSI A size. Our scan was saved
as a 24 bit color PDF file. The results
are as follows:
DPI Size (KB)
200 461
300 1153
400 1942
600 3780
The results showed that for each 100 dot per inch scanned the
file size doubled and in straight line proportion. The conclusion. If you do not need a high density of dots in
your archive scan, don’t. If file size
is not an issue but density is important, go ahead and scan at 300-400
DPI. Anything denser than 400 DPI there
is no visual difference. Unless a
requirement is to zoom into the drawing.
The more dots per inch the better image will be displayed on a zoomed in
look at the image.
The standard large format size is an Arch D size or 24” x
36” size document. This is 9X the size
of the sample 8 ½’ x 11” used. File
sizes also vary with how much data is on the page.
When this question is asked, there are many factors in contributing
to the ultimate file. The best way to
estimate your file size is to take an average drawing, scan it using the method
that optimally will work for your needs then decide if this size will work in
your environment. If not, modify your
scan parameters to fit your needs.