Re: Scanning multiple times (was Re: filmscanners: Vuescan gripes)

["Rob Geraghty" <harper@wordweb.com>]

"S. Matthew Prastein" <smprastein@earthlink.net> wrote:
> I seem to be missing something.  I have an Acer Scanwit 2740S, which
> requires multiple passes to do a multiple scan.  I thought that this
> was the right thing to do to get lower noise when scanning at 16x. so
> as to be able to average the input from successive reads. And, I
> thought this would help in extracting info from seriously underexposed
> negatives.   Am I all wet on this?

What Ed is saying is that having done a 16X scan once on a given frame
of film, you shold never have to do another 16X pass on the same frame.
Use Scan Memory to rescan the data you already have, or output the
raw file so you can recrop later without rescanning.

Multiscanning will give you lower noise as you suggested, and in the
process will give a little more signal.  Personally I have never done
a 16X scan.  With the LS30 and multipass scanning, I don't think there's
much benefit after about 4 passes.  If I had an LS2000 or more recent
scanner, single pass multiscanning would make 16X worthwhile.

It would be worth scanning the same frame at 4X, 8X and 16X and comparing
the result.

Rob