I always scan at maximum resolution and resize a copy later if needed.
harper@wordweb.com (Rob Geraghty) wrote:
> Derek wrote:
> [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
> bigger.
>
> >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
> magnification
> 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
>
>
> Rob Geraghty harper@wordweb.com
>
>
>
>
>
