Digital BW, The Print

Film base plus fog would be what is referred to the clear film that is at the edge of a negative that has been developed but not exposed to light. The fog is within the actual film itself not necessarily related to silver but the type of development that has occurred in regards to the emulsion on the film.  Maybe today its referred by another name.

Negatives can scan flat when you scan them as a positive, which may be a very good thing if you wish to take control of the imaging. The scanner usually employs some algorithm that adds contrast to it when you scan as a "negative". There are some instances that scanning as a negative makes it difficult. 

Generally with Piezography, the only black that prints is L value 0. And the only white that prints (actually does not get printed) is L value 255. So some Piezographers wish to get a tremendous amount of shadow and highlight detail by taking control of the values that are at or near 0 and 255. Scanning flat permits that. In this way L value 1 is lighter than 0, and 2 lighter than 1, etc. Also in the highlights you can actually see the differences between 254, 253, 252, etc..

When an artificial contrast curve is used by the scanner - a lot of the subtlety is pressed together in those areas.

If you can scan into 16 bit, you can create a curve (hopefully you can manage with one curve though that takes practice), and get the image into shape with respect to the highlights and shadows.

If your system does not quite differentiate between the lowest and highest L values, then the curve can be a little less specific.

Hope this helps...

Jon Cone
Piezography

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Ross" <rosscavanagh@...> wrote:
>
> I have question for Jon Cone regarding his setting the white point while scanning the negative. Forgive my ignorance of terminology, but what exactly do you mean by "film base + fog"? I've tried scanning my negatives as positives in the past and have come out with a very flat inverted image in PS requiring a lot of curves.
> 
> Thanks,
> 
> Ross
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "piezobw" <jon@> wrote:
> >
> > I agree with Walker about the positive scanning of negatives - it helps eliminate the scanner manufacturer's algorithm for converting a neg to a positive. I find this the best way to get out of the film what is there, without the scanner software imposing its own idea of what is there.
> > 
> > I'll add a penny to his two cents...
> > 
> > I usually set the white point on the film base + fog, and I set the black point on fully exposed film (leader for example). This way everything that has been exposed will exist within the dMin/dMax possibilities of the film.
> > 
> > 
> > Jon Cone
> > Piezography
> > 
> > --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Walker Blackwell <forums@> wrote:
> > >
> > > For BW, I often do raw (positive) drumscans of BW negs and inverted them in ACR. Then I import into Lightroom and do most of my global adjustments in there. I like it because it's non-destructive and faaast! (+ there is no duplicates. Just the raw scan files with non-destructive crop.)
> > > 
> > > + It gives me a more darkroom-esque workflow and I take save all my adjustments as templates, etc. For straight photography, it works really well for me.
> > > 
> > > Just my two cents,
> > > Walker
> > >
> >
>