[sane-devel] Re: Film scanners (was Re: Nikon Coolscan SCSI commands)

Jose Paulo Moitinho de Almeida moitinho@civil.ist.utl.pt
Mon, 23 Jul 2001 11:02:17 +0100

On Friday 20 July 2001 22:40, you wrote:
> Jose Paulo Moitinho de Almeida wrote:
> > The film type is printed of the edge of the negative. Yo can read it, but
> > normally the holders on film scanners don't allow to scan it (was that
> > the idea?)
> The question was:
> Is it necessary to change the negative type to find out the
> exact type or is it simple to find out the type by looking
> at the film.

Normally it is immediate to get the film type by visual inspection. But as 
Jonathan Buzzard put it, there may be a problem with "no-brand brands".

   > For a brand like Kodak, Fuji or Afga it is usually down the edge of the
   > strip. At least on 35mm film it is. So something like kodak gold 100-2
   > means Kodak Gold 100 ISO speed emulsion revision 2. With some of the
   > cheaper "own" brands you just get a series of numbers. Really old film
   > might have nothing.

I have been playing with a b/w film at home from the early sixties wich as 
FP3 on the edge, so I know it is an Ilford film. I may check some color 
negatives with my father, but if they are that old, either they have been 
kept in special conditions, or some colour tunning is necessary to account 
for fadding dyes. The standard mask will not be appropriate.

> When it is possible to read the type of the film from
> the negative than it is not necessary that changing the
> type of the negative does effect the preview
> without a new preview scan. That makes it much simpler
> to add media type functions.

I think that it should be possible, there may be some quality loss, but it 
should not be relevant for the preview.

Please note that I have mostly scaned colour slides but, if memory serves me 
right, the driver that is bundled with my Dual Scan II does not allow to 
select the type/brand of the colour negative. I think that they just use an 
average mask that may be corrected by the user.