[epson stuff snipped]
> If you scan a 24x36mm negative or slide at 300 ppi and
> then print it at 300ppi, what will be the size of the
> resulting picture? 24x36mm!
OK, perhaps the question may have been confusing due to some assumptions
I made. In Vuescan, AFAIK you don't get to alter the relationship between
PPI and the DPI which is encoded into the resulting file. There was an
option somwhere for "get the dpi from" I think, but I confess I haven't
investigated it. Anyway, using the default settings in Vuescan if you scan
with an LS30 you get a 2700dpi file.
By contrast, in Nikonscan you can scan at 2700ppi but output a file which
has a setting of 300dpi encoded into it - so the printed size would be much
>A 2700dpi scan implies a 9x magnification factor, so your 300ppi print
>will come out at 216x324 mm, or slightly larger than A4.
Yes, Nikonscan has a maximum "magnification" of 900%. It's not really
at all - it's just the relationship between the pixels and the encoded dpi.
>So always scan slides and negs at the best resolution you can get.
There's reasons I would want to do otherwise, but not when I want to print
the scan on my Epson. Presumably the answer to my question is that most
people (if not everyone) scans a source file at 2700dpi (or whatever their
maximum optical scanner resolution is) and change the output dpi later in
Photoshop or whatever editor they use.
Rob Geraghty email@example.com