[filmscanners] Re: Scanning negs vs. slides

["Arthur Entlich" <artistic-1@shaw.ca>]

As to the first question, I think Anthony touched upon this.

Slides are a final product designed to be projected as massive
enlargements under varied l ambient lighting conditions and varied
illumination levels.  They are projected into a surface which alters the
image from a transmissive for to a reflective one.

Projector screens are typically white or silver, meaning the only black
that exists in the projected image is the area where no light reflects
back from the screen, and if the room is fully dark.  Being that the
lighter areas of the projected image tend to illuminate the screen even
in areas where no lighting is supposed to fall, getting the necessary
contrast is difficult to maintain.  By providing an overly contrasted
image, by the time it gets translated to this viewed format, the result
might begin to represent something approaching the original contrast
levels and densities.

I have been suggesting for some time now that the industry needs to take
a new approach to providing positive films designed just for scanning.
These would have a density and contrast range which is better geared for
CCD scanning.  Since most new consumer labs are using digital/CCD
captures now to produce prints anyway, this film would not only provide
a positive image which provides certain advantages over negatives in
terms of translation to the final print image (a "standardized"
reference image) and the forever bothersome dye masking (yes, I know it
provides more accurate color by correcting for incomplete color
separation filtration in color films) but it could also be used for "at
home or office" scanning  without the many compromises the current crop
of slide films require due to their maximum density and contrast range.

The one thing this film could not be used for is projection, especially
for larger sizes and in less ideal room lighting conditions.

Personally, any of my images that are regularly projected get duped
anyway, and it seems a second generation transparency could be produced
using slide or duping films which brought the density and contrast back up.

I think its time for me to have a another little talk with Fuji....

Art

Julian Robinson wrote:

> I have a question that popped up while I was taking a close look at Fuji
> data sheets to confirm my prejudices.
>
> But first, email lists must be the absolute worst way of transferring
> information when emotion gets into it!!    Just slow enough and distant
> enough so that you can't get sufficient feedback for correction and shades
> of meaning (as you can if you try it face to face), but fast enough so that
> the emotion doesn't cool between goes (as it does in snail mail).
>
> My question:  The business of density ranges and recorded exposure range
> is, I thought, not a mystery at all if you look at the transfer
> curves.  There you can directly see what exposure range will go on the film
> and what density range is recorded on the film as a result.  So far so good.
>
> Now I always assumed that slides were geared up so that the density range
> on the slide was roughly the same as the original exposure range, so that
> scenes were recorded and viewed at about the original dynamic range.  But
> this is not so according to Fuji's curves, in fact slides are recorded with
> a density range around 10 times that of the original scene - i.e.
> significantly more contrast.  Now 10 times when log-ified is not a huge
> amount but still significant, so why is this done?
>
> Example - Provia 100 will record a scene exposure range of about log 1.8 (6
> stops) onto a film density range about log 2.8 (9 stops). Why?
>
> I can only assume that people find slides more pleasing when the contrast
> is enhanced, but why is this so universal, or have I missed something?
>
> Julian
>
> (note re negs, here a scene exposure range of about 11 stops is recorded on
> the neg as a density range of about 6 stops, so we can see how much the
> dynamic range is compressed i.e. 5 stops or 30:1.  This is why I wonder
> about the grain being re-expanded when contrast is restored).
>
>
>


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