Jan writes ...

> [...]
>
> I have another question regarding the tonal info in color negs. I
> learnt back in the analogue days that transparencies offer a
> higher tonal range than negs.
> And why would the fact that there is a bigger tonal range lead to
> the conclusion that more contrast needs to be applied? Or am I
> mixing tonal info and tonal range here? ...

  As a real example, you'd need compare a chrome and a negative, both taken
of the same subject.  Put both on a light table, and ask yourself which
shows the most contrast.  Your imprssion should be that the chrome exhibits
the most contrast (... in fact, the appropriate contrast ...), and the
negative would need be enhanced with respect to contrast.  This demonstrates
that tonal info (shadows, highlights) are compressed within the negative's
exposure ... exactly how many f/stops is difficult to measure, but I've read
13-14 f/stops for negs and 9-10 f/stops for chromes.  Another measure of
tonal range for chromes is the maximum optical density, which for any chrome
is no better than 3.1 to 3.3.  If you figure 3 f/stops per optical unit,
then you end up with ~10 f/stops.

  I'm not say scanning negs is better than chromes ... in fact the opposite.
But, if your subject included shadows on a sunny day, then for chromes, you
probably needed to sacrifice detail in either the shadows or the highlights.

hth & cheerios ... shAf  :o)
Avalon Peninsula, Newfoundland
www.micro-investigations.com


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