On Tuesday 17 August 2004 13:36, John Richard Smith wrote:
> Kaj Haulrich wrote:
> >Well John, now I'm learning to scan my old B/W negatives using
> >GIMP's acquire function. Xsane seems to work perfectly so far.
> > Of course I had to do a lot of experimenting first. One thing
> > that bothers me though is that I have to scan at resolution
> > 1200 in order to reasonably large pictures. But the quality is
> > quite amazing. And it seems to work best scanning with full
> > color range rather than standard negative. Wonder why.
>
> I found that too. I got better B+W pictures by scanning the
> original B+W source in colour and then using gimp to covert to
> greyscale. I sure don't know why that is unless the answer is
> that a colour scan, of necessity , grabs much more real data with
> which any programmes can work with and convert back to B+W. Just
> a guess.
>
> The choice of dpi seems to be a function of size of source area
> over degree of enlargement and therefore if for arguement's sake
> you want to extract an area in a picture the size of a postage
> stamp, but you want to enlarge it and use it again in another
> setting then it is necessary to choose a high dpi rate,
> naturally. That always supposes that the source of that postage
> size area has enough definition to allow for enlargement without
> undue degradation.
>
> I found I really did need a lot of CPU power to do all this.
> There is a hell of a lot of number crunching in image work,
> especially when you want to be getting on with scanning and
> sending print files to the printer as well. One reason why I'm
> contemplating AMD64 cpu's next.
>
> John
OK, my Athlon XP2100 works fairly well and 512 MB of RAM makes the
processing quite fast. When scanning a 35 mm B/W negative at 2400
resolution it takes about 20 seconds to complete. In order to keep
the resulting file size modest, I save the scans in jpeg with 90 %
quality, thus getting files around 1 MB. (Of course, when doing
multiple edits and saves I use .png to avoid picture degradation).
Not knowing if jpeg is here to stay, I save the really important
photos in raw format, but maybe that's overkill. Right now, I'm
trying to scan some old negatives in strange formats, such as 6x6
cm roll film shot with my Rolleiflex and some glass plates around
9x13 cm. My scanner doesn't come with a mask for those weird
things, so maybe I have to construct one myself. The fun goes on.
Kaj Haulrich.
--
*sent from a 100% Microsoft-free workstation*
* http://haulrich.net *
*Running Linux (Mandrake 10.0) - kernel 2.6.7*
____________________________________________________
Want to buy your Pack or Services from MandrakeSoft?
Go to http://www.mandrakestore.com
Join the Club : http://www.mandrakeclub.com
____________________________________________________
